Street Tree Species Selection - "Take it or Leave it"?

The Chronicle came out with a story today about a couple in the Richmond District who battled for almost 4 years to plant two trees in front of their home (replacing one tree that had blown over in a storm, and one that had dangerous structural problem). The story follows a pattern that we’ve seen in other areas of City government: residents try to do something with their home, business or property, and run into bureaucratic hassles. There’s a lot to digest in the article, but I’d like to focus on one aspect of the story.

This couple wanted to plant a “little gem magnolia”. Little gems are a dwarf cultivar of the Southern Magnolia (Magnolia grandiflora) that are generally considered appropriate for most locations, because of their relatively small size. However, according to the article, “DPW told the couple that the magnolia wouldn’t work because of its extensive root system”. Instead of giving the couple a list of permitted trees, DPW then suggested just one: Ceanothus (presumably Ceanothus ‘Ray Hartman”, which is the only cultivar of the species that can be grown into a small tree). When the couple rejected that idea and pushed for the magnolia, the City first consented (but required the couple to sign a legal agreement to assume liability for the tree), and then changed its mind, denying the planting permit entirely.

DPW ultimately relented, and allowed the couple to plant a sweet michelia (Magnolia doltsopa) as a compromise, but only after the Chronicle got involved.

Putting bureaucratic hassles aside, what strikes me about this story is how forceful the City is becoming with species selection. Ever since the City assumed responsibility for tree maintenance when the “StreetTreeSF” ballot initiative passed in 2008, DPW has gotten stricter in disallowing certain tree species, especially those that become very large or present above-average risk of failure. In general, that all makes sense (although as regular readers of sftrees.com know, I really think that an exception should be made for red flowering gums).

But this case takes things to an entirely new level. It’s one thing to limit tree selection to a list of trees that generally don’t present problems. It’s another to mandate the species that a homeowner can plant. If the article is accurate, this is a situation where a small tree was suggested, and the response was to reject the proposal and tell the homeowners to plant just one species.

I hope that this is a one-off situation, and that things haven’t gotten to the point where anyone who wants to plant a tree will be told what to plant - given one “take it or leave it” idea. Letting people plant what they want (and giving them a range of choices) has a number of benefits. First, people are more likely to look out for their tree if they got a tree that they love - more likely to water it in the summer heat (and I’ve seen some DPW trees that have died in summer heat waves) and more likely to help if the tree is knocked over by a truck or a winter storm. And second, it makes people happy, and connects them to their home and their neighborhoods.

Let’s be more flexible for residents who want to green our streets!

Taiwan Cherry - Rare and Beautiful! (2-24-25)

Richard Turner tipped me off to this beautiful tree at 171 Hartford (just downhill from 19th Street) in the Castro neighborhood. It’s Prunus campanulata (common name Taiwan cherry or Formosan cherry). More common in Southern California, but very rare here in San Francisco (I don’t know of another one in the City). Photo credits to Richard!

171 Hartford Street

Castro - Divisadero Tree Tour (2-15-25)

A busy thoroughfare, a quiet residential street, a dead-end road, and a schoolyard filled with native plants—all this in today’s tree walk. We have dubbed this neighborhood Castro-Divisadero, as it incorporates the triangle at the merging of Castro and Divisadero streets. It falls just beyond the Castro, Duboce Triangle, Corona Heights Park, Buena Vista Park, and Haight neighborhoods. Some surprisingly mature trees can be found along the way. 

Today’s walk begins at the main entrance to the McKinley Elementary School, 1025 14th Street. It heads east on 14th to Castro Street, then south along Castro to Henry Street. It continues west for half a block on Henry before returning to and crossing Castro, then north on the east side of Castro to Duboce Avenue. At Duboce, it crosses Castro and continues north on the west side of Castro to it’s merger with Divisadero Street. From there, it heads south on Divisadero to the end of Divisadero at 14th. The walk is a bit over a mile in length. 

Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 42. White arrows on the pavement provide directions whenever a turn is needed. 

The street addresses provided below will help when the chalk has faded. Many of the first trees on this walk are planted around the outer edges of the McKinley Elementary School playground (noted as McKinley below); some are planted around the Davies Hospital campus (noted as Davies below); others are planted in sidewalk pockets; and a few are planted within the front or rear gardens of homes along the route. 

14th Street, Divisadero to Castro, south side

1. 1025 - 14th   Mayten (Maytenus boaria), Chile (many trees along 14th Street, with gracefully pendant branches, resembling those of weeping willows)         

**Head down the steps or the ramp towards the school building** 

Santa Cruz Island ironwood (Lyonothamnus floribundus ssp. aspleniifolius)

2. 1025 - 14th   Santa Cruz Island ironwood (Lyonothamnus floribundus ssp. aspleniifolius), CA’s Channel Islands, except Catalina Island 

Owlswood Blue ceanothus (Ceanothus arboreus x thyrsiflorus ‘Owlswood Blue’)

3. McKinley     Owlswood Blue ceanothus (Ceanothus arboreus x thyrsiflorus ‘Owlswood Blue’), hybrid of California native species 

Blackwood acacia (Acacia melanoxylon), SE Australia (young tree with unusually rounded phyllodes) 

Meyer lemon (Citrus x meyeri), hybrid of mandarin and pomelo, both SE Asian species                       

4. McKinley     Toyon (Heteromeles arbutifolia), CA and SF native! (birds have already eaten the brightly colored fruits for which this small tree is known; commonly seen in natural areas in SF, particularly the Presidio and Bay View Hill. 

Coast redwood (Sequoia sempervirens)

5. McKinley     Coast redwood (Sequoia sempervirens), Big Sur to SW Oregon; CA coastal native (this species is the tallest tree in the world) 

6. McKinley     California buckeye (Aesculus californica), California & Oregon; a San Francisco native tree! (it’s just leafing out) 

California buckeye (Aesculus californica)

Castro Street, 14th to Henry, west side

7. McKinley     Southern magnolia (Magnolia grandiflora), SE USA (this species was planted extensively along Castro Street, on both sides, from here to Market Street; the largest trees, south of Henry Street, were planted in the early 70s)  

8. McKinley     African fern pine (Afrocarpus falcatus, formerly A. gracilior), E & S Africa 

9. McKinley     Sydney golden wattle (Acacia longifolia), E Australia (this species was used extensively in the early plantings of Golden Gate Park) 

Henry Street, west of Castro, north side

10. McKinley   Torrey pine (Pinus torreyana), San Diego County, and Santa Rosa Island, CA (this long-needled pine, though adaptable in cultivation, is the rarest pine species in the world, found only on the coast near La Jolla and Del Mar, and on Santa Rosa Island off Santa Barbara; these are among the largest specimens in SF) 

Torrey pine (Pinus torreyana)

11. McKinley   Canary Island pine (Pinus canariensis), Canary Islands (surprisingly uncommon in SF, these pines have even longer needles than the Torrey pines nearby) 

12. McKinley   London plane tree (Platanus x hispanica), hybrid of E USA species and Mediterranean species (this deciduous tree is among the most commonly planted trees in cities around the world outside the tropics) 

Henry Street, west of Castro, south side

Peppermint willow (Agonis flexuosa)

13. 265 Henry              Peppermint willow (Agonis flexuosa), SW Australia 

14. 150 Castro              Incense cedar (Calocedrus decurrens), CA native; Oregon to Baja (tree is in the rear garden on Henry; the wood         is used in construction and for making pencils) 

15. 150 Castro              Avocado tree (Persea americana), Mexico & Central America (tree is in the rear garden on Henry) 

corner store fruits - 14th and Castro

***Cross Castro carefully at the crosswalk; note the rows of Southern Magnolia stretching along Castro to the south*** 

Henry Street, east of Castro, south side

16. 197 Henry              Ginkgo (Ginkgo biloba), China (these distinctive deciduous trees are the last of an ancient lineage of gymnosperms) 

Henry Street, east of Castro, north side

17. 149 Castro              Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (row of 3 trees on Henry; first introduced in San Francisco) 

Castro Street, 14th to Duboce, east side

Monterey cypress (Hesperocyparis macrocarpa)

18. Davies        Monterey cypress (Hesperocyparis macrocarpa), Carmel, CA, native (one of the most widely planted conifers in coastal California; numerous mature trees border the Davies Hospital parking garage) 

19. Davies        Monterey pine (Pinus radiata), CA native: Año Nuevo, Monterey, Cambria, plus Cedros and Guadalupe islands, MX (several can be seen mixed with the Monterey pines around the parking garage; most widely planted coniferous tree in the world, mostly for lumber) 

20. 60 Castro   Sweetgum (Liquidambar styraciflua), E USA to Mexico & Central America (across the street; this tallest tree on the block is holding onto last year’s leaves, which will drop as this year’s leaves emerge) 

Brisbane box (Lophostemon confertus)

21. 36 Castro   Brisbane box (Lophostemon confertus), E Australia (this block of Castro is lined with this species, most planted at the time of the construction of Davies Hospital in the 1960s; some are among the largest in the city) 

***Cross Castro at the traffic signal*** 

Castro Street at Duboce, west side

22. 2 Castro     Blackwood acacia (Acacia melanoxylon), SE Australia (this young tree, situated far too close to the building, is likely a seedling of the mature specimen a few yards uphill on Duboce) 

Castro Street, Duboce to Divisadero, west side

23. 754 Duboce            Lombardy poplar (Populus nigra ‘Italica’), a narrow-growing cultivar of a Eurasian species (2 deciduous trees in the corner bed) 

24. 754 Duboce            Brush cherry (Syzygium australe, formerly S. paniculatum), E Australia 

a sidewalk square from 1931! (across from the silk oak near where Castro and Divisadero meet)

25. 9-11 Castro            Silk oak (Grevillea robusta), E Australia (across the street, in the walled yard to the south of the building; known for their bright yellow orange flowers in late spring in areas with a warmer climate, these two trees seldom flower due to the chill of the city) 

Divisadero Street, Castro to Duboce, east side

26. 170 Divisadero       Hollywood juniper (Juniperus chinensis ‘Torulosa’ or ‘Kaizuka’), E Asia 

27. 170 Divisadero       Olive (Olea europaea), Mediterranean Basin 

28. 154 Divisadero       Chinese windmill palm (Trachycarpus fortunei), China (3 trees) 

29. 154 Divisadero       Water gum (Tristaniopsis laurina), E Australia (this tree grows in stream-side locations in the wild, hence the common name; SF’s most commonly planted street tree) 

30. 140 Divisadero       Ponytail palm (Beaucarnea guatemalensis), Central America (a rare species in cultivation, particularly in SF) 

31. 140 Divisadero       Hybrid pōhutukawa in Māori (Metrosideros excelsa x kermadecensis), New Zealand mainland and Kermadec Islands (the rounded leaves, relatively few aerial roots, and winter flowers suggest that this tree is a hybrid) 

32. 126 Divisadero      Peruvian pepper tree (Schinus molle), Peru, Brazil, & Chile 

33. 108 Divisadero       Jacaranda (Jacaranda mimosifolia), Argentina, Bolivia (these heat loving trees are becoming more common in SF, especially in warmer areas of the city—all thanks to climate change) 

Duboce Avenue, Divisadero to Castro, north side

34. 760 Duboce            Willow-leaf peppermint (Eucalyptus nicholii), SE Australia (2 trees, mid-block on Duboce) 

35. 106 Divisadero       Japanese black pine (Pinus thunbergii), Japan and S Korea (tree is on Duboce at the corner) 

Japanese black pine (Pinus thunbergii)

Divisadero Street, Duboce to 14th, west side

36. 99 Divisadero        Tree fuchsia (Fuchsia arborescens), C America (this large shrubby fuchsia flowers all year in SF) 

37. 99 Divisadero        Hercules tree aloe (Aloidendron ‘Hercules’), hybrid of two S African species (note the diverse plantings in this garden designed by the talented Dan Carlson) 

38. 67 Divisadero        Purple-leaf plum (Prunus cerasifera), Eurasia (pink flowers usually appear by February; formerly SF’s most planted street tree; usually without leaves through fall and winter) 

39. 61 Divisadero        Hybrid hibiscus (Hibiscus rosa-sinensis), tropical Asia (not known to thrive in SF’s cool climate, but this specimen is doing well in a protected corner of the building) 

40. 55 Divisadero        Thornless honey locust (Gleditsia triacanthos ‘Inermis’), E USA 

41. 42 Divisadero        Indian laurel fig (Ficus microcarpa ‘Nitida’), S Asia to N Australia (the entire block, from here to 14th, is planted on both sides with this tree; formerly one of SF’s most planted trees) 

42. 16 Divisadero        Bailey’s acacia (Acacia baileyana), E Australia (this is usually among the earliest flowering trees in SF, always beginning in January with fluffy bright yellow flowers, which are now done on this fine specimen) 

The tour ends here, just a few yards from its start at McKinley Elementary School.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Oceanside Walking Tour

On yet another mild, dry winter day (will it ever rain again this season?), we visited the neighborhood known as Oceanview, in the southwestern quadrant of San Francisco. This is a densely built neighborhood, with houses close to the street, leaving little room for street trees. Fortunately, the neighborhood benefits from the trees that surround the Millie & Lovie Ward Recreation Center, which fills the block bounded by Plymouth and Capitol avenues and Montana and Lobos streets. The mature Monterey cypresses on the west, south, and east sides of the Rec Center are among the healthiest in the city, undoubtedly due to the extra rain and fog typical in this section of the Alemany Gap.  

A delightful surprise, to those of us not from the neighborhood, was the planted median on the long block of Minerva Street, just west of Plymouth; it’s filled with a variety of small trees and palms, flowering shrubs, succulents, and art.   

It was encouraging to note that Friends of the Urban Forest (FUF) has been planting young street trees throughout the neighborhood, wherever sidewalk space permitted. This is part of a concerted effort on the part of both the city’s Urban Forestry Division and FUF to provide more shade in areas of the city that have typically lacked tree cover. With a warming climate, the importance of trees to provide shade and cool the environment cannot be stressed enough. 

Today’s walk begins at the main entrance to the Millie & Lovie Ward Recreation Center at Capitol Avenue (cross is Minerva Street). It heads south on Capitol just past Lobos Street, then returns to Lobos and heads east to Plymouth Avenue, and north on Plymouth. At Minerva Street, the walk heads east up the gentle part of the hill to about midway, crosses the median at the red steps, and returns to Plymouth. It then continues north on Plymouth, west on Montana Street, and finally south on Capitol to the beginning of the walk at Minerva. This walk is about 1 mile in length. 

Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 32. White arrows on the pavement provide directions whenever a turn is needed. 

Capitol Avenue, Minerva to Lobos, east side

Monterey cypress (Hesperocyparis macrocarpa)

1. Rec Ctr        Monterey cypress (Hesperocyparis macrocarpa), Carmel, CA, native (opposite 545 Capitol; one of the most widely planted conifers in coastal California; mature trees surround the Rec Ctr on the west, south, and east)        

Jester conebush (Leucadendron ‘Jester’)

2. Rec Ctr        Jester conebush (Leucadendron ‘Jester’), hybrid of S African species (corner of Capitol & Lobos and Plymouth & Lobos        

 Capitol Avenue, south of Lobos, east side

Eureka lemon tree (Citrus x limon ‘Eureka’)

3. 438 Capitol  Eureka lemon tree (Citrus x limon ‘Eureka’) hybrid of S Asia species (not commonly grown in SF)

 4. 438 Capitol  Southern magnolia (Magnolia grandiflora), SE USA

 **Cross the street carefully**

 Capitol Avenue, south of Lobos, west side

5. Corner school grounds       Hybrid pōhutukawa in Māori (Metrosideros excelsa x kermadecensis), New Zealand mainland and Kermadec Islands (opposite 438 Capitol; the rounded leaves, relatively few aerial    roots, and winter flowers suggest that this tree is a hybrid)

 Lobos Street, Capitol to Plymouth, south side

6. 177 Lobos    Brisbane box (Lophostemon confertus), E Australia

 **Cross the street carefully**

 Lobos Street, Capitol to Plymouth, north side

7. Rec Ctr        Peppermint willow (Agonis flexuosa), SW Australia (opposite 171 Lobos)

   8. Rec Ctr        Santa Cruz Island ironwood (Lyonothamnus floribundus ssp. aspleniifolius), CA’s Channel Islands, except Catalina Island (opposite 171 Lobos; a number of these native trees have been planted on the slope above the sidewalk)

 9. Rec Ctr        Cajeput tree (Melaleuca quinquenervia), New Caledonia, New Guinea, NE Australia (opposite 159 Lobos)

Holm oak (Quercus ilex)

 10. Rec Ctr       Holm oak (Quercus ilex), Mediterranean Basin (several trees opposite 151 Lobos; a surprisingly uncommon tree in SF, despite its adaptability to our climate;

 11. Rec Ctr       Water gum (Tristaniopsis laurina), E Australia (opposite 139 Lobos; this tree grows in stream-side locations in the wild, hence the common name; SF’s most commonly planted street tree)

 12. Rec Ctr       Bronze loquat (Eriobotrya deflexa, syn. Rhaphiolepis deflexa), S China and Vietnam (opposite 131 Lobos)

13. Rec Ctr       Coast live oak (Quercus agrifolia), SF and CA native; Baja to Mendocino, always within 50 miles of the coast (2 trees opposite 119 Lobos; though native to SF, these specimens are not thriving as well as the nearby Holm oaks)

 14. Rec Ctr       Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (corner Lobos & Plymouth; first introduced in San Francisco; larger ones are around the corner on Plymouth)

 Plymouth Avenue, Lobos to Minerva, west side

15. Rec Ctr       Olive (Olea europaea), Mediterranean Basin (opposite 512 Plymouth)

 Minerva Street median, east of Plymouth, south side

Coast blueblossom (Ceanothus thyrsiflorus)

16. Median      Coast blueblossom (Ceanothus thyrsiflorus), coastal S Oregon to CentralCalifornia; a San Francisco native (opposite 554 Plymouth)

 17. Median      Red-tip photinia (Photinia x fraseri), hybrid (opposite 88 Minerva; more commonly seen as a dense shrub with red new foliage along CA freeways)

Mexican fan palm (Washingtonia robusta)

 18. Median      Mexican fan palm (Washingtonia robusta), S Baja & Sonora, Mexico (opposite 85 Minerva)

  19. Median      Pink melaleuca (Melaleuca nesophila), W Australia (opposite 71 Minerva)    

Giant yucca (Yucca gigantea, formerly Y. elephantipes)

 20. Median      Giant yucca (Yucca gigantea, formerly Y. elephantipes), Mexico & Central America (opposite 63 Minerva)

Torch aloe (Aloe arborescens)

 21. Median      Torch aloe (Aloe arborescens), S & SE Africa (opposite 57 Minerva; though the scientific name suggests that this is “tree-like”, it rarely is more than a big shrub; notable for its reliable flowering during CA winters)

 22. Median      Mediterranean fan palm (Chamaerops humilis), W Mediterranean Basin: Portugal & Morocco to Tunisia & Italy (opposite 55 Minerva; this is a young specimen that will grow into a low multi-trunked tree; it has the northernmost natural range of             any palm in the world)

 **Cross to north side of Minerva, using the red concrete steps; watch the traffic**

 Minerva Street median, east of Plymouth, north side

23. Median      Red escallonia (Escallonia rubra), S Chile and Argentina, all the way to Tierra del Fuego (opposite 30 Minerva; normally grown as a dense large shrub, this one has been pruned into an attractive multi-trunk tree)

 24. Median      Cabbage tree or tī kōuka in Māori (Cordyline australis), New Zealand (opposite 36 Minerva)

  25. Median      Monterey cypress (Hesperocyparis macrocarpa), Carmel, CA, native (opposite 80 Minerva; this tree is only about 10 years old; compare with the mature trees around the Rec Ctr)

 Plymouth Avenue, Minerva to Montana, east side

African fern pine (Afrocarpus falcatus, formerly A. gracilior)

26. 668 Plymouth        African fern pine (Afrocarpus falcatus, formerly A. gracilior), E & S Africa

 Montana Street, Plymouth to Capitol, south side

27. Rec Ctr       Pussy willow (Salix sp.), California (opposite 136 Montana; the flowers, resembling the paws of a kitten, will appear soon)

 28. Rec Ctr       Saratoga laurel (Laurus ‘Saratoga’), hybrid of Mediterranean and Atlantic species (opposite 148 Montana; several trees inside the fence; a selected form introduced     by Saratoga Horticultural Foundation)

Montana Street houses

  Montana Street, Plymouth to Capitol, north side

29. 158 Montana          Angel’s trumpet (Brugmansia ‘Charles Grimaldi’), Andes (tree is across the street, with large pendant, trumpet-like flowers; named for the late, well-known garden designer in SF)

 30. 194 Montana          Island oak (Quercus tomentella), California’s Channel Islands (a CA native) and Guadalupe Island, Mexico (this young tree represents a new species introduction that should thrive in the city’s climate)

 Capitol Avenue, Montana to Minerva, west side

31. 201 Capitol            Japanese camellia (Camellia japonica), E Asia (though usually grown as a shrub for its beautiful late winter/spring flowers, Japanese camellia is actually a small tree)

 32. 601 Capitol            After Dark peppermint willow (Agonis flexuosa ‘Jervis Bay Afterdark’), SW Australian cultivar (2 trees in sidewalk pockets; often less vigorous than the green-leafed species; compare with a green-leafed specimen of this species at #7 on this walk)

 This tour ends here, across the street from its start at the main entrance to the Rec Ctr.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Poppy Lane Buckeye

I was in Glen Park recently and decided to check out the massive California buckeye (Aesculus californica) on Poppy Lane - one of the quaint unpaved alleys in the Glen Park neighborhood. It’s looking great - I think it’s likely the largest California buckeye in the City. Check it out - Poppy Lane between Conrad and Diamond!

Poppy Lane

What a Find!

I love the hunt for great trees in San Francisco. Unlike many cities, where the local government determines what is planted, and entire avenues are planted with one species, San Francisco has always given residents the right to plant what they want (within reason), which over the years has contributed to a wonderful diversity of trees in the neighborhoods. You never know what you’ll find around the corner, a serendipity that contributes to my love of San Francisco streets. And the only thing better than finding an amazing tree is finding an amazing tree in a totally unexpected place.

That’s what happened in June of this year, when Richard Turner, Jason Dewees, Sairus Patel and I were chalking our 50th chalk tree on Nob HIll, a neighborhood famous for its many tiny alleys. As we were walking west on Sacramento Street, we came upon Golden Court, which is so small that it’s not even on many maps. It’s too small for cars - Golden Alley is actually a long sidewalk that leads to the addresses along the way.

We decided to check out the alley (single file!), and you can imagine our surprise to find an amazing specimen of a lacebark tree (Brachychiton discolor) near the end of the alley. This is a tree so rare in San Francisco that the four of us knew of only one other example in the entire city. This one was a large specimen in the bloom of health.

So the next time you’re at the Fairmont Hotel or Grace Cathedral, take a 3 or 4 minute stroll to Golden Court, to see San Francisco’s “city champion” lacebark tree!

Eureka Valley West Tree Tour

Who would have expected that the tree geeks would be rained out on a Saturday in late August? Yet, that is exactly what happened when Mike, Sairus, and Dick chose to meet at the corner of 18th and Storrie streets, a few blocks west of Castro Street, to explore the trees in this western corner of Eureka Valley. The clouds had been threatening on Friday and into the early hours of Saturday. Almost exactly at the appointed meeting time, light rains began, and continued for over an hour—all the result of a former typhoon that bypassed Japan in favor of a modest hit to California.  

With sidewalks too wet to accept chalk, the geeks decided to walk the route and photograph some of the outstanding trees to be seen on the streets and in private gardens along the way. This is a quiet neighborhood, on the far edge of the Castro District, with homes ranging from historic Victorian and Edwardian to trendy contemporary styles. Trees can be seen in abundance, as might be expected of this moderately upscale neighborhood with its well-educated population. Among the trees noted are some city champions, and some markedly uncommon trees for San Francisco.  

Today’s walk begins at the unnamed community garden on the southern side of the one-block-long Storrie Street, from Market to 18th streets. Previously a leftover strip of undeveloped land with topographical challenges, it has in recent decades evolved into a delightful public park, almost all at the hands of a local, born-in-San Francisco chap who tends the garden daily. (He’s happy to chat with anyone who drops in to see the garden.) The park is notable for some giant cottonwoods (Populus sp.) and a few eucalypts and their kin from Australia.  

We strolled west on 18th, passing the former Sha’ar Zahav Jewish synagogue before turning south onto 19th Street, which curves around and heads east after crossing Caselli Avenue. At Yukon Street, we noted the large Monterey pines (Pinus radiata) in Goat Hill Park on the far corner, before turning north on Yukon Street. We turned east (right) on Caselli and followed it to tiny Clover Lane, which rises to Thorp Lane. We followed Thorp east to its end at 19th, and headed east on 19th to Douglass Street. There we turned north, walking past the glorious Caselli Mansion at Douglas and Caselli. We ended our walk at 18th. Our walk was roughly a mile in length.  

We may return to this neighborhood for a properly chalked walk, but, in the interim, we hope you’ll enjoy some of the photographs taken along the way.

red flowering gum (Corymbia ficifolia) infloresence just about to open

and now opening!

a petunia in an 18th Street garden - a friend saw this picture and declared it “goth” :)

Fall color on 19th Street - a maple hybrid (probably Acer x freemani)

a gold medallion tree (Cassia leptophylla) on 19th Street

a Monterey pine (Pinus radiata) in front of the Caselli mansion

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Red Flowering Gums - San Francisco's Best Tree! Why have we stopped planting them?

Please join Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms, Mike Sullivan (author of Trees of San Francisco and webmaster of www.sftrees.com) and Richard Turner (retired editor of Pacific Horticulture) in declaring the last week of July as “red flowering gum week” in San Francisco.  This amazing tree is in full bloom now - we need to start planting it again! Spread the word:

WHEREAS red flowering gum trees have stunningly beautiful red, orange, pink or white flowers every summer that outshine any other tree in San Francisco; and

WHEREAS mature red flowering gums are large trees with leaves that remain on the tree year-round, and so are excellent contributors to the fight against climate change; and 

WHEREAS as natives of Western Australia, red flowering gums thrive in our cool coastal climate; and are one of the best adapted trees to San Francisco’s conditions;

WHEREAS the largest documented red flowering gum in Northern California, and the 2nd largest in the United States, is in San Francisco in San Francisco’s St. Francis Woods neighborhood in the Monterey Boulevard median near the intersection of Junipero Serra Boulevard; and

WHEREAS red flowering gums bloom from early July through September, but reach their peak bloom in late July;

WHEREAS the flowering season of red flowering gums coincides with peak tourist season in San Francisco, offering visitors Instagram-worthy brilliant floral displays;

WHEREAS, despite these many positive attributes, the City of San Francisco has virtually stopped planting red flowering gum trees;

NOW, THEREFORE, BE IT RESOLVED, that the many fans of this amazing tree declare the last week of July now and henceforth to be “Red Flowering Gum Week” in the City and County of San Francisco, dedicated to promoting the many advantages of, and sharing images and information about, San Francisco’s best tree!

in front of Mission High School in the Mission District

Divisadero and O’Farrell

Harrison & 18th Streets in SOMA

Monterey Boulevard in St. Francis Woods - this street is lined with red gums!

Fort Mason - Bay Street

Southeast Bernal Heights Tree Tour

 We return for a fourth walk on the slopes of Bernal Heights, this time to the southeastern corner of the neighborhood. Known for its mix of 19th, 20th, and 21st century residences, the neighborhood also offers dramatic views to the south and east, and a lively shopping district along Cortland Avenue. Despite the notoriously narrow streets, trees are common and diverse, including two that are “city champions” - the largest of their kind in the City. 

Today’s walk begins at the northwest corner of Nevada Street and Cortland Avenue, and heads north (uphill) on Nevada to Powhattan Avenue, then east on Powhattan one block to Nebraska Street. Head south (downhill) on Nebraska to Cortland, and then east on Cortland for about half a block. The walk continues on the south side of Cortland on Bronte Street. (Be careful crossing Cortland as there is no crosswalk at this point; it may be safer to go further east and use the crosswalk at Bradford Street.) Head south (now, uphill) on Bronte to Jarboe Avenue, then west on Jarboe to Putnam Street, and north  (downhill) on Putnam to Cortland. The walk ends one block west at Cortland and Nevada. This walk is about 1 ½ miles in length, with some moderately steep slopes. 

Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 23. White arrows on the pavement provide directions whenever a turn is needed.

Nevada Street, Cortland to Powhattan, west side

1. 170 Nevada             Sweetgum (Liquidambar styraciflua), E USA to Mexico & Central America

Mock-orange or tobira (Pittosporum tobira)

 2. 147 Nevada             Mock-orange or tobira (Pittosporum tobira), Japan & Korea (tree is across the street; clusters of intensely fragrant, white flowers; typically grown as a large shrub, this one is a city champion, largest in SF) 

3. 134 Nevada             Bronze loquat (Rhaphiolepis deflexa, syn. Eriobotrya deflexa), S China and Vietnam 

Santa Cruz Island ironwood (Lyonothamnus floribundus ssp. aspleniifolius)

4. 114 Nevada             Santa Cruz Island ironwood (Lyonothamnus floribundus ssp. aspleniifolius), CA’s Channel Islands, except Catalina Island (this one is flowering heavily; others can be seen along Cesar Chavez Street, just north of Bernal Heights) 

5. 104 Nevada             Purple (or blue) potato bush (Lycianthes rantonnetii), Paraguay (typically a large shrub, this one has been trained into a multi-trunked, tree-like form; flowers are produced all year) 

seen along the way!

Powhattan Avenue, Nevada to Nebraska, south side

6. 900 Powhattan        Champak (Magnolia champaca) S & SE Asia (small, magnolia-like flowers, appearing in summer, are intensely fragrant; these three trees have been pruned in an unfortunate manner) 

Cabbage tree (Cussonia spicata)

7. 2 Nebraska              Cabbage tree (Cussonia spicata), S Africa (tree is on Powhattan; a curious, uncommonly grown tree in SF; the palmately lobed leaves are distinctive; note the thick stems developing flower buds on the right-most trunk) 

**Note this richly planted corner garden at Powhattan and Nebraska, created and maintained by the talented Elliot Goliger of Artisans Designs. 

Nebraska Street, Powhattan to Cortland, west side

8. 2 Nebraska              Jacaranda (Jacaranda mimosifolia), Argentina, Bolivia (the big show of blue purple flowers is just beginning, now that the leaves have fallen; these heat loving trees are becoming more common in SF, especially in warmer areas of the city—all thanks to climate change) 

Hercules tree aloe (Aloidendron ‘Hercules’)

9. 2 Nebraska              Hercules tree aloe (Aloidendron ‘Hercules’), hybrid of two S African species 

10. 38 Nebraska          Mediterranean fan palm (Chamaerops humilis), Mediterranean Basin: Portugal & Morocco to Tunisia & Italy (this is a young specimen that will grow into a low multi-trunked tree; northernmost natural range of any palm in the world) 

11. 48 Nebraska          Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (first introduced in San Francisco; these two specimens are among the largest in the city) 

12. 26 Nebraska          Hybrid crape myrtle (Lagerstroemia hybrid.), Asia (watch for the flowers that will be opening soon, and for the glorious fall foliage color)  

Cortland Avenue, Nebraska to Bradford, north side

Canary Island date palm (Phoenix canariensis)

13. 1410 Cortland       Canary Island date palm (Phoenix canariensis), Canary Islands, Spain (a “grove” of three trees in this large yard; this is the species seen in the median of Upper Market Street and along the Embarcadero) 

***Please cross Cortland carefully, perhaps using the crosswalk at Bradford Street, half a block to the east. Bronte Street is midway between Nebraska and Bradford, on the south side of Cortland.***

Bronte Street, Cortland to Jarboe, west side

African fern pine (Afrocarpus falcatus, formerly A. gracilior)

14. 16 Bronte               African fern pine (Afrocarpus falcatus, formerly A. gracilior), E & S Africa (this is the largest specimen in the city: a city champion) 

Queen palm (Syagrus romanzoffiana)

15. 20 Bronte               Queen palm (Syagrus romanzoffiana), S Brazil (one tall mature specimen and one much younger specimen) 

16. 36 Bronte               Elegant water gum (Tristaniopsis laurina ‘Elegant’), E Australia (this selection of the water gum has longer, glossier leaves than the species) 

Sweetshade tree (Hymenosporum flavum)

17. 62 Bronte               Sweetshade tree (Hymenosporum flavum), E Australia (the fragrant yellow flowers appear in late spring through much of the summer; this tree often grows tall and narrow at first, eventually broadening its canopy) 

Putnam Street, Jarboe to Cortland, east side

Giant bird-of-paradise (Strelitzia nicolai)

18. 77 Putnam            Giant bird-of-paradise (Strelitzia reginae), E South Africa (note the huge, blue and white flowers on this young tree, compared to the much smaller, bright orange and blue flowers on the nearby common bird-of-paradise, which grows as a shrub) 

19. 75 Putnam            Washington thorn (Crataegus phaenopyrum) E USA (note the white flowers that will become colorful fruits in late fall, but beware of the long thorns on the branches) 

pretty flowers along our walk

20. 59 Putnam            Mayten (Maytenus boaria), Chile (five trees with gracefully pendant branches, resembling those of weeping willows) 

21. 42 Putnam            Purple-leaf plum (Prunus cerasifera), Eurasia (two trees across the street) pink flowers usually appear by February; formerly SF’s most planted street tree; often seen without leaves through fall and winter) 

Glossy privet (Ligustrum lucidum)

22. 14 Putnam            Glossy privet (Ligustrum lucidum), S China 

Cortland Avenue, Putnam to Nevada, south side

23. 1302 Cortland       Purple hopseed tree (Dodonaea viscosa ‘Purpurea’), native throughout tropical and subtropical parts of the world 

Today’s walk ends here, kitty-corner from its beginning.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Nob Hill Tree Tour (6-1-24)

For our 50th (!) chalk tree tour, we chose Nob Hill - one of the most iconic of the city’s many historic neighborhoods. Crowned by the magnificent 20th century Gothic-style Grace Cathedral, the hilltop is the home of the city’s finest hotels, the only Gilded Age mansion to survive the 1906 earthquake and fire (built by James Flood), and beautiful Huntington Park—a formal oasis in the heart of the city. As we chalked this tour on the first day of Pride Month, colorful flags and banners waved from all the hotels, along with rainbow-painted steps from Taylor Street up to the Cathedral’s main entrance, all in honor of the city’s diverse and inclusive culture. With the exception of the Flood mansion, all of the buildings in this predominantly residential neighborhood were built after the 1906 earthquake; the diversity of architectural styles is captivating. For such a dense neighborhood, trees are surprisingly plentiful and unexpectedly diverse.

Today’s walk is a simple one. It begins at the Interfaith Memorial Labyrinth at the top and to the side of the steps at Grace Cathedral, which is on Taylor Street between California and Sacramento streets. The Labyrinth is ringed with some particularly fine purple leaf plums (a Prunus cerasifera cultivar). From the Labyrinth, follow the walkway north towards the Canary Island date palm, which is tree #1. Once down at street level, head west on Sacramento past Jones Street to Golden Court. After exploring this fascinating pedestrian lane, continue west on Sacramento past Leavenworth Street to Kimball Place, another intriguing lane. Then, return to Leavenworth and head north to Clay Street, east on Clay to Taylor, and back south on Taylor to the Cathedral. Cross Sacramento and Taylor streets to enter Huntington Park for a delightful spot to sit and rest your feet. This walk is almost a mile and a half in length.

Grace Cathedral’s labyrinth, surrounded by purple leaf plum trees (Prunus cerasifera)

 Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 24. White arrows on the pavement provide directions whenever a turn is needed.

Left to right: Jason Dewees, Mike Sullivan, Sairus Patel and Richard Turner (in front of a king palm - (Archontophoenix cunninghamiana)

 The street addresses provided below will help when the chalk has faded. Most of the trees on this walk are planted in sidewalk pockets; a few are planted within the front or rear gardens of homes along the route. And a few are found in the quaint and curious dead-end lanes that are found in this neighborhood—reminiscent of the mythical Barbary Lane in Armistead Maupin’s Tales of the City.

Canary Island date palm (Phoenix canariensis)

 2. 1230 Sacramento                 Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (tree is across the street; first introduced in San Francisco)

 **Note the beautifully shaped bougainvillea on the ornate building next door to 1230.**

 3. N side of Cathedral             Italian buckthorn (Rhamnus alaternus), Mediterranean Basin (this is typically a shrub but has been trained into a tree form here)

 **Note the well-planted vertical garden, filled with a variety of ferns, on the north wall of the Cathedral School for Boys, just east of Jones.**

 Sacramento Street, Jones to Golden Court, south side

4. 1155 Jones                Indian laurel fig (Ficus microcarpa ‘Nitida’), southern Asia to N Australia (the entire block is planted with this tree, and other blocks as well; formerly one of SF’s most planted trees)

 5. 1329 Sacramento     Allspice magnolia (Magnolia x foggii), hybrid of two Asian species, M. figo and M. doltsopa (tree is growing in the narrow and dark gap between the buildings; despite the deep shade, it is flowering heavily; enjoy the intense fragrance of the white blossoms; it is likely a city champion)

a dragon guarding the trees on Golden Court

 Golden Court, south of Sacramento

Lacebark tree (Brachychiton discolor)

6. 10 Golden    Lacebark tree (Brachychiton discolor), Eastern Australia (this rarely planted tree is 25 years old, and is a “City Champion” - the biggest of its species in San Francisco. We know of only one other lacebark tree in SF, so this was an unexpected and delightful surprise!

 7. 8 Golden      Iochroma fuchsioides, Andes of Ecuador and Columbia (typically known as a long-flowering shrub in SF, it will grow to tree-like dimensions in the Andes; it has no common name)

Lilly pilly tree (Syzygium smithii)

 8. 9 Golden      Lilly pilly tree (Syzygium smithii, previously known as Acmena smithii), E Australia (note the clusters of tiny white flowers and pale lavender fruits)

Karaka (Corynocarpus laevigatus) leaves

 9. Golden        Karaka (Corynocarpus laevigatus), New Zealand

 10. Golden       Douglas-fir (Pseudotsuga menziesii), West Coast & Rocky Mountains (tall conifer with needle-like leaves, almost hidden by all the shrubs; a CA native tree!)

 **Continue west on Sacramento, past Leavenworth, to Kimball Place**

 Kimball Place, south of Sacramento

11. South end of Kimball        Cabbage tree or tī kōuka in Māori (Cordyline australis), New Zealand

Coast redwood (Sequoia sempervirens)

Coast redwood (Sequoia sempervirens), Big Sur to SW Oregon; CA coastal native (2 trees rising out of this crowded space; this species is the tallest tree in the world)

Japanese maple (Acer palmatum), Japan, China, Korea

 **Return to Leavenworth and head north**

 Leavenworth Street, Sacramento to Clay, east side

Red-flowering gum (Corymbia ficifolia)

12. 1202 Leavenworth             Red-flowering gum (Corymbia ficifolia), SW Australia (produces bright red, orange, or pink flowers in summer; among the best and showiest of trees in SF’s urban forest; we cannot understand why the city is no longer planting this amazing tree!)

Mike, looking incredulous that the Public Works Department has banned the planting of SF’s most amazing tree!

 13. 1228 Leavenworth             Brisbane box (Lophostemon confertus), E Australia

 14. 1250 Leavenworth             River wattle (Acacia cognata), SE Australia

 15. 120 Leavenworth             King palm (Archontophoenix cunninghamiana), E Australia

One-sided bottlebrush (Calothamnus quadrifidus)

One-sided bottlebrush (Calothamnus quadrifidus), Western Australia (this is usually a large shrub, not a tree; rarely seen in SF gardens)

 Clay Street, Leavenworth to Jones, south side

16. 1385 Clay               Olive (Olea europaea), Mediterranean Basin (4 young trees)

Ginkgo (Ginkgo biloba)

 17. 1357 Clay               Ginkgo (Ginkgo biloba), China (last of an ancient lineage of gymnosperms) Note that there is another ginkgo just past this one, and this 2nd ginkgo is a female, bearing malodorous fruits.

 18. 1340 Clay               Chitalpa (xChitalpa tashkentensis), hybrid of two native USA species, one from the SW deserts and one from the Midwest (3 small trees are in sidewalk pockets across the street; this hybrid species typically languishes in SF’s cool summer climate; reflected heat off the building appears to benefit these specimens; watch for soft lavender pink flowers later in the summer)

 19. 1301 Clay               New Zealand Christmas tree, pōhutukawa in Māori (Metrosideros excelsa), New Zealand (several trees on both sides of Clay and along Jones; this tree flowers most reliably in the summer months, which would be      Christmas time in NZ, south of the equator)

New Zealand Christmas tree, pōhutukawa in Māori (Metrosideros excelsa)

 Clay Street, Jones to Taylor, south side

20a. 1250 Jones            Elegant water gum (Tristaniopsis laurina ‘Elegant’), E Australia (tree is on Clay; this selection of the water gum has longer, glossier leaves than the species)

 20b. 1216 Clay             Avocado tree (Persea americana), Mexico & Central America (a small tree is poking out of the entry courtyard of the building across the street)

 21. 1217 Clay               Pygmy date palm (Phoenix roebelenii), southern China, Laos, Vietnam

22. 1217 Coppertone Indian hawthorn (Rhaphiolepis ‘Coppertone’), hybrid of two E Asian species, Eriobotrya deflexa and Rhaphiolepis indica (3 round-headed trees across the street; new spring growth is coppery in color)

 Taylor Street, Clay to Sacramento, west side

Chinese elm (Ulmus parvifolia)

23. 1137 Taylor            Chinese elm (Ulmus parvifolia), China, Korea, Japan, and Vietnam

Huntington Park, all sides

24. Huntington Park block     London plane tree (Platanus x hispanica, formerly Platanus acerifolia), hybrid of E USA species and European species (this tree surrounds the park, and there are many more throughout the neighborhood, almost all of them pollarded as this one is; this hybrid species is among the most commonly planted tree in cities around the world).

25. Huntington Park, south side Ray Hartman ceanothus (Ceanothus ‘Ray Hartman’), hybrid of CA native species (clusters of soft blue flowers in winter/early spring). This one is one of the largest we know of in San Francisco - it may be a “City Champion”!

Ray Hartman ceanothus (Ceanothus ‘Ray Hartman’)

 Today’s walk ends here. Take time to enjoy the quiet beauty of Huntington Park, where there are a variety of other trees, including a number of blackwood acacias (Acacia melanoxylon) and a stunning specimen of Ray Hartman ceanothus (Ceanothus ‘Ray Hartman’) next to Mrs James Flood’s fountain in the southeast corner of the park.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Bunya bunya in West Portal Removed by Owner - Another one of SF's Best Trees is Gone

This is what you’ll see now…

Another very sad story for San Francisco tree lovers - the majestic bunya bunya tree (Araucaria bidwillii) at 201 Vicente Street in the West Portal neighborhood, has been removed by the owner. Nothing left but a stump. I don’t have the details as to why, but I do know it was done without a permit - which is a no no, since the tree was a “significant tree” that was close enough to the sidewalk to require a City permit for removal. The Public Works Department is aware of the violation and will be dealing with the owner.

This is the second of San Francisco’s “top 10” trees to be lost within the last year - the amazing California buckeye at Willard Street North and McAllister died of unknown causes last winter, and now this. I previously ranked the California buckeye as my #2 in the City and this bunya bunya was #4. Both trees are highlighted in my Trees of San Francisco book. So sad to lose these two landmarks!

Trees of Angel Island (2-24-24)

I did a bike trip to Angel Island today, not thinking I would see a lot of tree diversity. As expected, the island is full of coast live oaks, toyon and the occasional California buckeye and California bay. But what I didn’t expect was to find some unusual specimen trees near the Angel Island Immigration Museum.

To get to the immigration museum, you head downhill from the Perimeter Road at a point on the northeast part of the island. On the walk down, on your left you’ll see a couple of stately spotted gums (Corymbia maculata).

spotted gums (Corymbia maculata)

Continue down the road to the open area below the museum, and to your far left is a large bunya bunya tree tree (Araucaria bidwillii), native to Australia. Bunya bunyas are rare in San Francisco, and one of our best was just cut down in West Portal at Vicente and Wawona, so this was a welcome sight.

bunya bunya tree (Araucaria bidwillii)

At the other end of the clearing near the museum is a close relative of the bunya bunya - a Norfolk Island pine (Araucaria heterophylla), also large and mature. It wouldn’t surprise me if they were planted at the same time.

Norfolk Island pine (Araucaria heterophylla)

And in between the two Araucaria, facing the water, two Canary Island date palms (Phoenix canariensis).

Canary Island date palms (Phoenix canariensis)

Angel Island used to be full of blue gum eucalyptus trees (Eucalyptus globulus), but 80 acres of eucalyptus were removed in the 1990s - among other things, they were thought to be a fire hazard that created risk for the nearby historic buildings. However, there are still beautiful specimens of this tree to be found around the island.

blue gum eucalyptus (Eucalyptus globulus)

And lastly, the most common tree on the island - coast live oak (Quercus agrifolia).

coast live oak (Quercus agrifolia)

Trees of Mexico City (1-25-24)

I visited Mexico City with my family in late January 2024 - we stayed in the Roma Norte neighborhood, and didn’t stray very far from there, so this blog may not be representative of the entire city’s trees.

It was my first time in Mexico City. I had heard that the city was very leafy, and I found that to be accurate. In fact, at least in the Roma Norte neighborhood, the street trees are so dense that it’s not easy to get an Instagram-worthy photo of an individual tree! This link from Google maps of a street not far from our hotel will give you a sense of this part of Mexico CIty.

We visited one of the city’s botanical gardens (Jardin Botanico del Bosque de Chapultepec), but I found it underwhelming. The cactus and agave collections were attractive, but the park is relatively small (13 acres), and very few tree specimens were labeled.

The three species that dominated the streets of our neighborhood were shamel ash (Fraxinus uhdei), glossy privet (Ligustrum lucidum) and American sweetgum (Liquidambar styraciflua). Two of the three are native to Mexico - shamel ash is native from west-central Mexico to Costa Rica, and sweetgum is found in disjointed areas from central Mexico to Nicaragua.

shamel ash (Fraxinus uhdei)

The ash trees were the most abundant of all, which saddened me a bit to think that the emerald ash borer is marching across the continent, killing every ash it encounters, and eventually I suspect will make it to Mexico City.

shamel ash (Fraxinus uhdei) - closeup of leaves and samaras (fruits)

glossy privet (Ligustrum lucidum) - closeup

American sweetgum (Liquidambar styraciflua) - closeup of leaves

Another tree that was very common on city streets was weeping fig (Ficus benjamina). It’s very rare as a street tree in my native San Francisco, but I saw it everywhere in Mexico City.

weeping fig (Ficus benjamina) - closeup

weeping fig (Ficus benjamina)

Occasionally I ran across orchid trees (Bauhinia purpurea) in bloom as street trees.

orchid tree (Bauhinia purpurea)

Not a tree, but another plant I saw everywhere in our neighorhood was split leaf philodendron (Thaumatophyllum bipinnatifidum).

When we ventured out of Roma Norte into other neighborhoods, the canopy thinned out a bit (and I also started to see some more unusual tree species. Below is a Cook pine that we encountered in the Condesa neighborhhood, not far from the city’s botanical garden. This tree always leans towards the equator (a discovery by botanist Matt Ritter in 2017), and this one was duly leaning south!

Cook pine (Araucaria columnaris) on Calle Juan de la Barrera near the corner of Avenida Mazatlan in the Condesa neighborhood

We visited Casa Gilardi, a home designed by minimalist architect Luis Barragan-designed - the family that has owned it since it was built it gives private tours. It’s in the San Miguel Chapultepec neighborhood, and if you’re into architecture or home design, I really recommend it. Inside the open air courtyard of the home is a large jacaranda (Jacaranda mimosifolia), a tree native to Argentina and Bolivia - but very popular in Mexico City.

the indoor pool at Casa Gilardi

a hallway at Casa Gilardi

jacaranda (Jacaranda mimosifolia) in the courtyard at Casa Gilardi

A couple of days later I saw what I think it the largest jacaranda I’ve ever seen - the address is 208 Jalapa in the Roma Norte neighborhood.

a huge jacaranda (Jacaranda mimosifolia) at 208 Jalapa in Roma Norte

At 7,350 feet in altitude, Mexico City isn’t tropical, but since it rarely has freezing temperatures, there are lots of palm trees that do well here. Canary Island date palms (Phoenix canariensis) were pretty common.

Canary Island date palm (Phoenix canariensis)

And not far from our hotel (at the intersection of Calle Jalapa and Calle Puebla in Roma Norte), we found a corner full of bismarck palms (Bismarckia nobilis), a tree native to Madagascar.

bismarck palm (Bismarckia nobilis)

Compared to my native San Francisco, there were relatively few eucalyptus trees. We did see a beautiful eucalyptus relative - a spotted gym (Corymbia maculata) on Avenida Insurgentes Sur near Avenida Alvaro Obregon in Roma Norte.

spotted gym (Corymbia maculata) - Avenida Insurgentes Sur

Bailey's Acacia - first sign of a San Francisco Spring!

It’s a little late this year - normally this tree blooms in January in San Francisco. Bailey’s acacia (Acacia baileyana) is a tree from eastern Australia that blooms with striking yellow flowers. It’s the first of our trees to bloom - next will be the plum trees (later in February), then the cherries (March), and even later (April/May) the hawthorns.

As you can see from the partially hidden street sign, this tree is at the corner of 17th and Shrader Streets in the Cole Valley neighborhood.

And it has one more claim to fame - this tree was the one photographed by author and botany professor Matt Ritter for his (fantastic) book “A Californian’s Guide to the Trees Among Us”.

Fairmount Hill Tree Tour (2-3-24)

Between showers on a mostly windless day, we chose a relatively quiet neighborhood wedged between the northeastern extent of Glen Park and the southern extent of Noe Valley. It covers the lower slopes of a hill known as Fairmount, one of the many hills that make up the San Miguel Hills in this part of the city. We were pleased with the diversity of trees in this small neighborhood. But, the real draw is the variety of residential architecture, from stunning and beautifully restored Victorians to modest cottages, along with some ‘50s-‘60s apartment buildings. Laidley Street is known for its collection of radical contemporary architecture from the ‘80s and ‘90s. Take time to appreciate this diversity in residential design. 

Today’s walk is a simple one. It begins on Whitney Street, at its terminus at Chenery Street. It heads north on Whitney for two blocks to Randall Street, then continues on Randall for two more blocks to Harper Street, and heads uphill on Harper to Laidley Street. From there it heads southeast-ish on Laidley to Miguel Street, downhill on Miguel to Whitney, and then north again on Whitney for a few yards. This walk is almost a mile and a half in length.

 Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 34. White arrows on the pavement provide directions whenever a turn is needed. 

Whitney Street, Chenery to Fairmount, east side

1. 298 Chenery            Brisbane box (Lophostemon confertus), E Australia (tree is on Whitney)

 2. 263 Whitney           Cajeput tree (Melaleuca quinquenervia), New Caledonia, New Guinea, E Australia (3 trees, including 1 across the street; feel the distinctive spongy bark)

 3. 249 Whitney           Ginkgo (Ginkgo biloba), China (last of an ancient lineage; there are many ginkgos in the neighborhood, including some very young ones on Miguel)

Chinese elm (Ulmus parvifolia)

 4. 249 Whitney           Chinese elm (Ulmus parvifolia), China, Korea, Japan, and Vietnam

 5. 229 Whitney           African fern pine (Afrocarpus falcatus, formerly A. gracilior), E & S Africa (peeking around the construction fence)

 6. 219 Whitney           Victorian box (Pittosporum undulatum), E Australia (common in the neighborhood; intensely fragrant white flowers cycle through the year)

 7. 191 Fairmount        Tree fuchsia (Fuchsia arborescens), C America (peeking over the fence on Whitney; this large shrubby fuchsia flowers all year in SF)

 8. 191 Fairmount        Peppermint willow (Agonis flexuosa), SW Australia (2 trees is on Whitney)

 Whitney Street, Fairmount to Randall, east side

Water gum (Tristaniopsis laurina)

9. 159 Whitney           Water gum (Tristaniopsis laurina), E Australia (this tree grows in stream-side locations in the wild, hence the common name; SF’s most commonly planted street tree)

 10. 155 Whitney          Mayten (Maytenus boaria), Chile

 11. 119 Whitney          Coast redwood (Sequoia sempervirens), Big Sur to SW Oregon; CA coastal native (this species is the tallest tree in the world)

 12. 197 Randall           Plume albizia (Paraserianthes lophantha, formerly Albizia lophantha), SW Australia (within the fenced garden of the property on Randall; a feathery-leafed small tree with pale yellow flowers in clusters; this species has become a weed in the western portions of Golden Gate Park and above Sutro Baths)

 **Cross Whitney and continue a short distance on Randall**

 Randall Street, Whitney to Sanchez, south side, then north side

13. 201 Randall           Ray Hartman ceanothus (Ceanothus ‘Ray Hartman’), hybrid of CA native species (just beginning to open its blue flowers)

 14. 207 Randall           Indian laurel fig (Ficus microcarpa ‘Nitida’), S Asia to N Australia (formerly one of SF’s most planted trees)

 **Cross Randall**

 15. 200 Randall           Brazilian pepper tree (Schinus terebinthifolia), Brazil, Argentina, Paraguay

 16. 228 Randall           Lemon bottlebrush (Callistemon citrinus), E Australia

 17. 228 Randall           Giant yucca (Yucca gigantea, formerly Y. elephantipes), Mexico & Central America

 18. 240 Randall           New Zealand Christmas tree, pōhutukawa in Māori (Metrosideros excelsa), New Zealand (this tree flowers most reliably in summer months, which would be Christmas time in NZ, south of the equator)

 Randall Street, Sanchez to Harper, north side

Olive (Olea europaea)

19. 250 Randall           Olive (Olea europaea), Mediterranean Basin

 20. 250 Randall           Meyer lemon (Citrus x meyeri), hybrid of mandarin and pomelo, both SE Asian species (in the rear yard, heavily laden with fruit)

Meyer lemon (Citrus x meyeri)

 21. 270 Randall           Sweet viburnum (Viburnum odoratissimum), S, SE, and E. Asia (very uncommon in SF; usually a shrub)

 ** Cross Harper**

 Harper Street, Randall to Laidley, west side

Bailey’s acacia (Acacia baileyana ‘Purpurea’)

22. 76 Harper              Bailey’s acacia (Acacia baileyana ‘Purpurea’), E Australia (this is usually among the earliest flowering trees in SF, always beginning in January with fluffy bright yellow flowers)

 ** Cross Laidley**

 Laidley Street, Harper to Fairmount, south side

Chinese windmill palm (Trachycarpus fortunei)

23. 128 Laidley           Chinese windmill palm (Trachycarpus fortunei), China (a fine specimen)

 24. 117 Laidley           Texas privet (Ligustrum japonicum ‘Texanum’), E. Asia (2 trees across the street; city champions; these are usually seen as large sheared hedges)

 25. 138 Laidley           Cork oak (Quercus suber), Spain & Portugal (3 trees; the bark of this tree provides the cork used in wine bottles)

Cork oak (Quercus suber) - closeup of bark

 26. 140 Laidley           Black locust (Robinia pseudoacacia), E USA (this deciduous tree will have fragrant white flowers in spring)

 ** continue on the lower side of Laidley**

 Laidley Street, Fairmount to Miguel, east side (lower side)

a beautiful Victorian home on Laidley Street

27. 237 Fairmount      Willow-leaf peppermint (Eucalyptus nicholii), SE Australia (2 trees, one on each side of Laidley)

 28. 233 Laidley           Primrose tree (Lagunaria patersonii), Norfolk and Lord Howe islands (soft pink flowers will appear later in the year)

 29. 224 Laidley           Rusty-leaf fig (Ficus rubiginosa), E Australia (across the street)

Glossy privet (Ligustrum lucidum)

 30. 279 Laidley           Glossy privet (Ligustrum lucidum), S China (2 trees)

 Miguel Street, Laidley to Whitney, northeast side

31. 201 Miguel            Tree aloe (Aloidendron barberae, formerly Aloe bainesii), S Africa to Mozambique (this specimen appears to be variegated, but the effect is due to sunscald)

Tree aloe (Aloidendron barberae, formerly Aloe bainesii)

 32. 219 Miguel            Bronze loquat (Rhaphiolepis deflexa, syn. Eriobotrya deflexa), S China and Vietnam

 Whitney Street, north from Miguel, west side

33. 268 Whitney          Jacaranda (Jacaranda mimosifolia), Argentina and Bolivia (watch for the big show of blue purple flowers in summer; these heat loving trees are becoming more common in SF, especially in warmer areas like the Mission District—thanks in partto climate change)

 34. 260 Whitney          Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (many fine specimens of this tree can be seen throughout the neighborhood; first introduced in San Francisco)

 Today’s tree walk ends here, just a few yards north of its beginning at Whitney and Chenery.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford and Environs. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Pacific Heights West Tree Tour

On a crisp December morning, we returned to the western end of Pacific Heights, a neighborhood filled with well-kept Victorian homes, a delightful shopping district, one of the finest branch libraries in the city, and one of the few remaining single-screen movie houses (the Vogue) in town. For this tour we were happy to be joined by Josh Gevertz, Arboretum Director at Cypress Lawn Cemetery in Colma (home to some amazing trees - it was recently recognized as a Level I arboretum by Morton Arboretum’s international ArbNet program - take the virtual tree tour here).

 Today’s walk begins in front of the elegant Presidio Branch Library, at 3150 Sacramento Street, and heads east on Sacramento to Baker Street, south on Baker to Pine Street, east on Pine to Lyon Street. The walk then turns south on Lyon for half a block, crosses Lyon to the east side, then heads north on Lyon to Sacramento, and finally east on Sacramento back to the Library. This walk is a little over one mile in length.

 Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 25. White arrows on the pavement provide directions whenever a turn is needed.

 Sacramento Street, Lyon to Baker, north side

Flame tree (Brachychiton acerifolius)

1. 3150 Sacramento    Flame tree (Brachychiton acerifolius), E Australia (a bold allee of six trees at the Presidio branch library; trees may lose their leaves just before flowering)

 Baker Street, Sacramento to California, west side

2. 1819 Baker              Southern magnolia (Magnolia grandiflora), SE USA (many in this block)

Southern magnolia (Magnolia grandiflora)

 3. 1817 Baker              Little Gem magnolia (Magnolia grandiflora ‘Little Gem’), SE USA (this selection of southern magnolia has smaller leaves, smaller flowers, and matures at a smaller size; compare with #2)

 4. 1815 Baker              Japanese maple (Acer palmatum), Japan, China, Korea (these trees have been pruned into a loose hedge lining the edge of the front garden)

 5. 1813 Baker              Brush cherry (Syzygium australe, formerly S. paniculatum), E Australia

  Irish yew (Taxus baccata ‘Fastigiata’)

 6. 1813 Baker              Irish yew (Taxus baccata ‘Fastigiata’), Irish cultivar of Eurasia & N Africa parents

 7. 1811 Baker              Eastern dogwood (Cornus florida ) E North America (not always the best choice for coastal California, but this one already has flower buds for next spring)

 California Street, west of Baker, north and south sides

8. 3000 California       Indian laurel fig (Ficus microcarpa ‘Nitida’), S Asia to N Australia (formerly one of SF’s most planted trees)

blue Atlas cedar (Cedrus atlantica ‘Glauca Fastigiata’)

 9. 3001 California       Fastigiate blue Atlas cedar (Cedrus atlantica ‘Glauca Fastigiata’), Atlas Mountains of Morocco & Algeria (note the narrow upright habit of the branches)

   Blue Ice yellowwood (Podocarpus elongatus ‘Monmal’), S Africa

 Baker Street, California to Pine, west side

10. 1710 Baker            Chinese windmill palm (Trachycarpus fortunei), China (across the street)   

Chinese windmill palm (Trachycarpus fortunei)

 11. 2896 Pine               Peppermint willow (Agonis flexuosa), SW Australia (tree is on the east side of Baker)

 Baker Street, Pine to Bush, west side

12. 1653 Baker            Modesto ash (Fraxinus velutina ‘Modesto’), SW North America (this cultivar discovered in Modesto, CA)

 13. 1611 Baker            London plane tree (Platanus x hispanica, formerly Platanus acerifolia), hybrid of E USA species and European species; it is among the most commonly planted trees in cities around the world; there are many in this neighborhood)

Japanese maple (Acer palmatum)

 14. 1611 Baker            Japanese maple (Acer palmatum), Japan, China, Korea (one of the largest in the city)

 15. 1611 Baker            Australian tree fern (Sphaeropteris cooperi, formerly Cyathea cooperi), SE Australia

 Bush Street, Baker to Lyon, north side

16. 2810 Bush              Prickly melaleuca (Melaleuca styphelioides), E Australia (note the tiny prickly leaves and spongy park; white flowers appear in summer; this is one of the biggest in town)

Prickly melaleuca (Melaleuca styphelioides)

 Lyon Street, south of Bush, west side

17. 1515 Lyon             Carob (Ceratonia siliqua), E Mediterranean Basin (there are several trees in this block; seed pods can be used to make a chocolate substitute—though       not recommended for true chocolate lovers)

 18. 1511 Lyon             Monterey cypress (Hesperocyparis macrocarpa), Carmel, CA, native (one of the most widely planted conifers in coastal California; note the trunk is covered with English ivy, which should be removed for the health of the tree)

tree-themed art at Little School (1520 Lyon)

 ** cross the street carefully**

 Lyon Street, south of Bush, east side

19. 1590 Lyon             Victorian box (Pittosporum undulatum), E Australia (intensely fragrant white flowers cycle through the year)

 Lyon Street, Bush to Pine, east side

Holm oak (Quercus ilex)

20. 1644-46 Lyon        Holm oak (Quercus ilex), Mediterranean Basin (a surprisingly uncommon tree in SF, despite its adaptability to our climate; these 2 trees are city champions)

 21. 1652 Lyon             Italian bay tree or Grecian laurel (Laurus nobilis), Mediterranean Basin (leaves of this tree are the bay leaves used in cooking)

 Lyon Street, Pine to California, east side

22. 2296 Pine               Glossy privet (Ligustrum lucidum), S China (tree is on Lyon)

 23. 1740 Lyon             Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (many fine specimens of this tree can be seen throughout the neighborhood; first introduced in San Francisco)

 Lyon Street, California to Sacramento, east side

24. 1812 Lyon             Chinese elm (Ulmus parvifolia), China, Korea, Japan, and Vietnam

 Sacramento Street, Lyon to Baker, south side

Olive (Olea europaea)

25. 1832 Lyon            Olive (Olea europaea), Mediterranean Basin (trees are on Sacramento)

 Today’s tour ends here on Sacramento, across the street and a few doors west of the Presidio Branch Library, where it began.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford and Environs. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Top photos of this blog's first decade!

I noticed recently that this blog just had a 10 year anniversary - my first post was August 30, 2013. I scrolled through the decade of posts, and found some photos that made me smile. Here are my top sftrees.com photos from the last 10 years:

Spotted gum (Corymbia maculata) adjacent to the Mission Pool at 19th Street between Guererro and Valencia. What a spectacular tree!

The largest Monterey cypress in the country! That’s me under the tree - In March 2021 I did a pilgrimage to see this amazing tree. It’s located at 751 Pescadero Creek Road in Pescadero - about 8 miles inland from Highway 1.

May 2020 - Jason Dewees (left), Richard Turner (right) and me on our Potrero Hill tour, next to a purple smoke tree (Cotinus coggygria ‘Royal Purple’). That’s a box of chalk in my hand. This was in the depths of the pandemic, so we were doing our chalk tree tours with masks.

The yellow-blooming New Zealand Christmas tree (Metrosideros excelsa) at 1221 Stanyan Street. My favorite individual tree in San Francisco.

A silk oak leaf on the sidewalk at 3520 18th/Valencia in the Mission

A red flowering gum (Corymbia ficifolia) on Monterey Boulevard in St. Francisco Woods. I love this species in San Francisco more than any other. Why is the City restricting the planting of this tree??!

Garage on Grove Street in the NOPA neighborhood

A stately wine palm (Jubaea chilensis) at the Sunnyside Conservatory on Monterey Boulevard. It takes a LONG time for this palm species to get this tall.

And another palm - this time a Mexican fan palm (Washingtonia robusta) in MissionBay

A doodle, courtesy of Jason Dewees

The California buckeye (Aesculus californica) at 2694 McAllister/Willard Street - largest and probably oldest of its species in San Francisco. Sadly, this tree died over the 2022/2023 winter. Here it is in glorious bloom in June 2020.

A dawn redwood (Metasequoia glyptostroboides) in the Arnold Arboretum in Boston in August 2021 - that’s my sister Patricia under the tree for scale. The Arnold Arboretum organized the effort to bring seeds back from China after the tree was discovered in the 1940s, and this tree was planted in 1948 when the seeds arrived. This is the largest one in the arboretum, and since their trees were planted first, it may be the largest dawn redwood in the United States!

sidewalk imprint of a London plane leaf on Page Street in the Haight-Ashbury neighborhood

California buckeye (Aesculus californica) on Poppy Lane in Glen Park

tulip tree (Liriodendron tulipifera) at the corner of Kearny and Vallejo on Telegraph Hill

gold medallion tree (Cassia leptophylla) at 227 Cole in the NOPA neighborhood. This one is the “City Champion” - biggest of the species in San Francisco

Beautiful garage door artwork at 523 Precita near Precita Park (the owner is the artist!)

  Monterey pine (Pinus radiata) at 214 Santa Clara Avenue. This specimen is the largest in the Western Hemisphere!

My husband and I took a trip to Sicily in April 2022 - this is a Moreton bay fig (Ficus macrophylla v. columnaris) in the Palermo botanical gardeny. That’s me standing behind one of the buttressing roots of the tree.

a carob tree (Ceratonia siliqua) in a field in Sicily

a silk floss tree (Ceiba speciosa) in Prospect Park in the Dogpatch neighborhood

a lonely volunteer California poppy in a San Francisco sidewalk

Row of Victorians off Page Street in the Haight Ashbury neighborhood

and just down the street on Page, Spiral aloe (Aloe polyphylla) at 1124 Page Street

the four of us! Jason Dewees, Sairus Patell, Mike Sullivan and Richard Turner

a lovely Guadalupe palm (Brahea edulis) at 333 Sussex Street in Glen Park

take a rock in Telegraph Hill!

Precita Park/Peralta Heights Tree Tour

Sunny, warm, and windless—a perfect October day in San Francisco, particularly after the past four uncommonly cool months. We chose a relatively little known neighborhood for today’s walk: Peralta Heights, a hilly neighborhood on the northeastern slope of Bernal Heights. This is a fairly warm pocket of the city, with quirky architecture and a surprisingly diverse array of trees to be enjoyed.  

Today’s walk begins in front of the Precita Park Cafe & Grill, at Alabama Street and Precita Avenue, and heads east on Precita to Florida Street, then crosses Precita and returns to Alabama. It then heads south on Alabama to Mullen Street, east (and slightly uphill) on Mullen all the way to Montcalm Street, then west on Montcalm to Alabama, and finally north on Alabama back to Precita. This walk is a little under one and a half miles in length.  

Numbered trees are labeled with common and scientific names and country of origin, all written in white chalk on the sidewalk; accompanying numbers, in blue, run from 1 to 43. White arrows on the pavement provide directions whenever a turn is needed. 

Beautiful garage door artwork at 523 Precita (the owner is the artist!)

Precita Avenue, Alabama to Florida, south side

1. 508 Precita  Saratoga laurel (Laurus ‘Saratoga’), hybrid of Mediterranean and Atlantic species (selected form introduced by Saratoga Horticultural Foundation) 

2. 548 Precita  Trident maple (Acer buergerianum), E China, Taiwan, Japan (note the heavy production of the winged seeds, called samaras; likely due to the exceptional rainfall of the past winter)

Canary Island date palm (Phoenix canariensis)

 3. 552 Precita  Canary Island date palm (Phoenix canariensis), Canary Islands, Spain (a young specimen, barely showing a trunk but providing plenty of shade; this is the species seen on Market Street and along the Embarcadero)

 Precita Avenue, Florida to Alabama, north side

4. 523 Precita  Silver dollar gum (Eucalyptus polyanthemos), E Australia (the leaves on young shoots have the approximate size and shape of a silver dollar)

Silver dollar gum (Eucalyptus polyanthemos)

5. 523 Precita  Sweet michelia (Magnolia doltsopa), Himalayas (the brown buds in the leaf axils will become large white, intensely fragrant flowers in winter)

Precita Avenue at Alabama Street, center island

Mexican fan palm (Washingtonia robusta)

6. Precita & Alabama             Mexican fan palm (Washingtonia robusta), S Baja & Sonora, Mexico (3 tall trees in the triangle where Precita and Alabama meet)

Alabama Street, south of Precita, west side

Cajeput tree (Melaleuca quinquenervia)

7. 1600 Alabama         Cajeput tree (Melaleuca quinquenervia), E Australia to Papua New Guinea (3 trees; feel the distinctive spongy bark)

Alabama Street, Precita to Mullen, east side

8. 1619 Alabama         Australian willow or wilga (Geijera parviflora), inland E Australia (this tree generally prefers the warmth of the eastern parts of the city)

Washington thorn (Crataegus phaenopyrum)

9. 1625 Alabama         Washington thorn (Crataegus phaenopyrum) E USA (note the colorful fruits, but beware of the long thorns on the branches)

10. 1627 Alabama       Ginkgo (Ginkgo biloba), China (a fine multi-trunked specimen, one of many in the neighborhood; last of an ancient lineage)

11. 1639 Alabama       Sweetgum (Liquidambar styraciflua), E USA to Mexico & Central America

Closeup of bark - Evergreen pear (Pyrus kawakamii)

12. 1653 Alabama       Evergreen pear (Pyrus kawakamii), Taiwan (only in cold winters does this species lose its leaves in San Francisco)

Mullen Avenue, Alabama to Peralta, south side

13. 40 Mullen              Peruvian pepper tree (Schinus molle), Peru & Chile

14. 70 Mullen              Karo (Pittosporum crassifolium), New Zealand

Mullen Avenue, Peralta to Franconia, north side

15. 131 Mullen            Monterey cypress (Hesperocyparis macrocarpa), Carmel, CA (across the street, along the sloping walkway; a California native, and one of the three most commonly planted trees in SF’s parks)

Mullen Avenue, Franconia to Montcalm, north side

16. 201 Mullen            Valley oak (Quercus lobata), California (at the top of the Franconia Steps; very rare in SF)

17. 211 Mullen            Pearl acacia (Acacia podalyriifolia), E Australia (the first flowers of the season are opening)

Gold medallion tree (Cassia leptophylla)

18. 239 Mullen            Gold medallion tree (Cassia leptophylla), SE Brazil (in full bloom)

***The next four trees are survivors from the exceptional garden of Tom and Jeong, who moved away some years ago***

19. 285 Mullen            Chinese windmill palm (Trachycarpus fortunei), China (2 trees)

Chinese windmill palm (Trachycarpus fortunei)

20. 285 Mullen            Beaked yucca (Yucca rostrata), Mexico and Texas

21. 285 Mullen            Tree aloe (Aloidendron barberae, formerly Aloe bainesii), S Africa to Mozambique (this may be the tallest specimen in the city)

22. 285 Mullen            Mountain cabbage tree (Cussonia paniculata), E South Africa (note that the right branch has begun to drop its leaves as the curious flowers develop)

Montcalm Street, Mullen to Franconia, north side

23. 100 Mullen            Marina strawberry tree (Arbutus ‘Marina’), hybrid of Mediterranean species (2 trees on Montcalm; this hybrid was first introduced in San Francisco and named for the Marina District)

24. 110 Montcalm       Coast redwood (Sequoia sempervirens), Big Sur to SW Oregon; CA coastal native (this species is the tallest tree in the world)

24b. 128 Montcalm     Elegant water gum (Tristaniopsis laurina ‘Elegant’), E Australia (this selection of the water gum has longer, glossier leaves than the species)

25.150 Montcalm        Avocado tree (Persea americana), Mexico & Central America

A guerrilla carving of a stairway fence post!

***The next seven trees are survivors from the exceptional garden of Geoff and Chip, who moved away many years ago***

26. 198 Montcalm       Trumpet bush (Tecoma hybrid), hybrid of tropical American species (this is actually a large shrub, but here it towers over the sidewalk)

27. 198 Montcalm       Pindo palm (Butia odorata), SE Brazil & Uruguay

28. 198 Montcalm       Guadalupe palm (Brahea edulis), Guadalupe Island, Mexico (this    palm is perfectly adapted to SF; it has been used in the median of Cesar Chavez Street in the Mission District)

29. 198 Montcalm       Australian fan palm (Livistona australis), E Australia

30. 198 Montcalm       King palm (Archontophoenix cunninghamiana), E Australia

31. 198 Montcalm       Norfolk Island palm (Rhopalostylis baueri), Norfolk Island & Kermadec Islands

Norfolk Island palm (Rhopalostylis baueri)

32. 198 Montcalm       Desert fan palm (Washingtonia filifera), S California, Arizona, and N Baja (generally uncommon in SF, as it prefers more summer heat; compare the fatter trunk and the greater number of thread-like filaments on the leaves of this species vs the tall Mexican fan palms seen in the rest of this block of Franconia)

Montcalm Street, Franconia to Peralta, north side

Italian stone pine (Pinus pinea)

33. 206 Montcalm       Italian stone pine (Pinus pinea), Mediterranean Basin (the source of pine nuts/pignoli)

34. 205 Montcalm       Nikau or shaving brush palm (Rhopalostylis sapida), New Zealand (the young tree is across the street)

35. 259 Peralta             Flannel bush (Fremontodendron californicum), California, Arizona, N Baja (tree is on Montcalm at the corner of the park; beware of the fine hairs on the leaves; they can be irritating)

36. 259 Peralta             Hollywood juniper (Juniperus chinensis ‘Torulosa’ or ‘Kaizuka’), E Asia (tree is on Montcalm at the corner of the park, behind the flannel bush)

37. 229 Montcalm       California buckeye (Aesculus californica ), California & Oregon; a San Francisco native tree! (tree is across the street, to the left of the continuation of Peralta Avenue

Montcalm Street, Peralta to Alabama, north side

38. 300 Montcalm       Blue Atlas cedar (Cedrus atlantica ‘Glauca’), Atlas Mountains of Morocco & Algeria (2 trees)

39. 306 Montcalm       Japanese maple (Acer palmatum), Korea and Japan (2 trees)

40. 308 Montcalm       Bronze loquat (Rhaphiolepis deflexa, syn. Eriobotrya deflexa), S China and Vietnam

41. 329 Montcalm       Lemonwood or tarata (Pittosporum eugenioides), New Zealand (tree is across the street)

Ginkgo (Ginkgo biloba) - female fruits

42. 366 Montcalm       Ginkgo (Ginkgo biloba), China (there are many ginkgos in the neighborhood; however, this one is a female, hence the foul-smelling fruit in autumn)

Alabama Street, Montcalm to Mullen, east side

43. 1669 Alabama     European weeping birch (Betula pendula), Eurasia & N Africa (not usually well-adapted to SF, but this specimen is outstanding)     

European weeping birch (Betula pendula)

This tree walk ends here. To return to its beginning, continue north for one more block to the Precita Park Cafe & Grill.

Our regular commercial: This walking tour was organized by Mike Sullivan, author of The Trees of San Francisco and webmaster of www.sftrees.com; Jason Dewees, horticulturist at Flora Grubb Gardens and author of Designing with Palms; Richard Turner, retired editor of Pacific Horticulture magazine and Sairus Patel, soon to be author of Trees of Stanford and Environs. You can follow Mike and Jason on their tree-themed Instagram pages at @sftreeguy and @loulufan. Richard edited another great book on San Francisco trees: Elizabeth McClintock’s Trees of Golden Gate Park. If you’re a tree enthusiast, buy all four of these books!

Trees of Copenhagen

I visited Copenhagen in July 2023, and found some remarkable trees in the four days that I was there, all in the central part of the city. Some were in Copenhagen’s very nice botanical garden, some in the King’s Garden, one in the city’s best art museum (!), and one in a pot just outside the home where we stayed. See below!

Lavalle hawthorns (Crataegus X lavallei) adjacent to the Little Mermaid

Perhaps the most famous tourist attraction in Copenhagen is the “Little Mermaid”. Some of our friends told us not to bother, but we were strolling along the water on our first day in the City, and ran across it. Just adjacent to the Little Mermaid was a small grove of Lavalle hawthorns (Crataegus X lavallei).

The King’s Garden (also known as Rosenborg Garden) in central Copenhagen is the oldest and most visited park in central Copenhagen - it was established in the early 17th century as the private garden of King Christian IV's Rosenborg Castle, which is adjacent. It’s full of stately mature trees that are happy in northern Europe.

White willow (Salix alba) in the King’s Garden

Common lime or European lime (Tilia X Europaea) in the King’s Garden

I don’t normally expect to find landmark trees in art museums, but just inside the entrance to the Glyptoteket (Copenhagen’s best art museum) was this nice example specimen of a Canary Island date palm (Phoenix canariensis).

Canary Island date palm (Phoenix canariensis) in the Glyptoteket

And Copenhagen has a lovely botanical garden in center city. It was raining off and on the day I visited, but in between the showers I found some trees worth noting. Just inside the gate on the left was an empress tree (Pawlonia tomentosa) - easily identifiable by the huge leaves and distinctive seeds.

empress tree (Pawlonia tomentosa)

empress tree - closeup of leaves and fruits

If you stay to the left after entering the garden, eventually you will reach this sweet chestnut tree (Castanea sativa). I didn’t find man of these in Scandinavia on our trip, so it caught my eye.

sweet chestnut (Castanea sativa)

sweet chestnut (closeup - leaves and fruits)

I think the most impressive grouping of trees were on a small hill near the center of the garden. Side by side were two trees that are actually fairly close relatives - a dawn redwood (Metasequoia glyptostroboides) right next to a coast redwood (Sequoia sempervirens). The coast redwood is the tallest tree in the world, and the dawn redwood was thought to have been extinct (known only from fossil records) until a specimen was discovered in central China in 1941.

A dawn redwood (Metasequoia glyptostroboides) on the left, right next to a coast redwood (Sequoia sempervirens) on the right

And just behind these two, another close relative of both - a giant sequoia (Sequoiadendron giganteum), native to the Sierra Nevada Mountains of Central California. This is the tree that is the most massive tree in the world, and it was in the bloom of health here in Copenhagen!

giant sequoia (Sequoiadendron giganteum)

We stayed very close to “Churchillparken” (Churchill Park) in Copenhagen, and as I meandered there one day, I ran across this spectacular specimen of sycamore maple (Acer pseudoplatanus). We don’t see this tree much in my hometown of San Francisco, so it was a treat to find it (and many others nearby).

sycamore maple (Acer pseudoplatanus) in Churchillparken (Churchill park)

And not too far away, next to one of the many canals, a weeping willow (Salix babylonica).

weeping willow (Salix babylonica) in Churchill Park

And finally, I think it’s a little cold for this tree in Copenhagen, but just outside the home where we were staying was this baby monkey puzzle tree (Araucaria araucana). I’m sure it will be brought inside for the winter!

monkey puzzle tree (Araucaria araucana)

Reunited with an old friend - American beech

I grew up in a maple/beech climax forest in Herkimer County, New York. I could walk out my door and follow trails leading into the forest behind our home, and within minutes I’d be deep in a dark forest of American beech trees (Fagus americana). I absolutely loved these trees - stately, with beautifully smooth grey bark, and beautiful leaves - one nature writer wrote that “an unearthly pale pure green clothes the tree in a misty nimbus of light”.

Sadly, since I left the northeast, American beech trees have been suffering from beech bark disease, disease that causes mortality and defects in the trees. I tried to find my old friends, the gigantic smooth-barked giants of my childhood, but they were all dead - I saw occasional stumps, but nothing else.

But it wasn’t all sad - I remember clearly planting a beech sapling in the 1970s in a clearing just behind our home in Poland, New York. A few weeks ago I visited that exact spot to see if it was still there, and was so happy to see it thriving. That’s me with my tree in the photo above.

One reason I was happy to find my old friend is that I hadn’t seen one of his kind in a long time. You’ll never see an American beech in the Bay Area - the tree can’t handle the compacted soils of our cities, and I suspect 8 months without rainfall is also tough for a tree that’s used to the rainy East Coast. All of the beech trees in urban and suburban California are European beech (Fagus sylvatica).