Self-Guided Tree Walk: Old Palo Alto

Sign up to take an arborist-led Tree Walk. Tree Walk starting point map.

The Old Palo Alto Tree Walk begins at Gamble Garden Center, 1431 Waverley Street, Churchill Avenue parking entrance.

View the Symbols Legend

1. Coulter Pine (Pinus sabiniana)

~ 444 Churchill Avenue, pine on the right

Unusual for this area, this pine with 8–12” needles crowded at the ends of thick twigs is native to central and Southern California between 3000’ and 6000’. Native Americans once gathered and ate the large seeds. The shorter-needled pine to its left is a Monterey Pine (Pinus radiata).

2. Coast Live Oak (Quercus agrifolia)

~ 474 Churchill Avenue, large street tree on Cowper Street near the corner

Native mainly to California’s coastal ranges, Coast Live Oak is frequently associated with California Bay Laurel, Madrone, Toyon, and other native oaks. It grows best in well-drained soil. The acorns that drop in the fall can produce young oaks very readily. Native oaks do not tolerate summer water and should not be planted in lawn areas.

3. Valley Oak (Quercus lobata)

~ 1515 Cowper Street, front courtyard of the house

Considered the monarch of California oaks by virtue of its size, age, and beauty. Valley Oaks appear in the diaries of many early visitors to California. Describing the open groves of the Santa Clara Valley in 1796, English explorer George Vancouver wrote: “For about twenty miles, it could only be compared to a park which had originally been closely planted with the true old English oak.”

4. Snakebark Maple (Acer capillipes)

~ 475 Coleridge Avenue, 3 young street trees on Cowper Street

Green and silver striped bark is the unusual feature of this attractive maple tree. One of these three trees is probably a different cultivar from the other two as its leaf shapes and fall color patterns are different. Snakebark Maples are known for growing well in shady locations.

5. London Plane Tree (Platanus x acerifolia)

~ 508 Coleridge Avenue, 5 street trees on Cowper Street

This fast-growing tree is used extensively as a street tree in Palo Alto due to its deep roots and tolerance of the urban environment. Notice the beautiful bark and large arching canopy. ‘Columbia’ is the best-performing cultivar for the immediate Bay Area; it is least susceptible to anthracnose leaf drop suffered by other cultivars in the warm, wet spring.

6a. Canary Island Pine (Pinus canariensis)

~ 1631 Cowper Street, left front corner

This pine tree native to the Mediterranean is an excellent replacement for Monterey Pines and other conifers subject to borers. It tolerates a dry summer and is relatively pest free.

6b. Marina Madrone (Arbutus ‘Marina’)

~ 1631 Cowper Street, between the front door and the driveway

Related to, but more adaptable than, the native Madrone (Arbutus menziesii), this Arbutus tolerates typical gardening conditions and regular watering as long as the soil is well-drained. Take a good look at the beautiful bark and, if it is the right season, the colorful fruit. The largest known specimen was planted in a San Francisco garden in 1942 and has reached a height and spread of 40’.

7. Purple Beech (Fagus sylvatica ‘Atropunicea’)

~ 505 Lowell Avenue, inside the back fence on Cowper Street next to 1669 Cowper Street

The Latin (and scientific) name for the beech genus Fagus comes from a Greek word for eating. The oil-rich, peanut-sized nuts found inside the woody prickled fruit case have been favored as a treat since the Stone Age.

8. Flowering Pear (Pyrus calleryana ‘Bradford’)

~ 468 Lowell Avenue, 2 street trees

A white-flowering ornamental pear, it usually grows to about 40’ and has beautiful spring bloom and late fall color in December. The ‘Bradford’ cultivar has very poor structure and if not pruned extensively, trees can literally fall apart. ‘Aristocrat’ and ‘New Bradford’ are good replacements. These cultivars are also resistant to fire blight leaf disease.

9. Coast Redwood (Sequoia sempervirens)

~ 1709 Waverley Street, tall tree right of the driveway on Lowell Avenue

When you plant this tree, remember it is one of the tallest tree species in the world. Count on branch spread at the base (tip to tip) of 14–30’ wide. Centuries-old natives surpass 350’ high, but 70–90’ can be expected in 25 years. In its native coastal ranges of California and Oregon, the Coast Redwood collects fog with its needles, which drips down and provides moisture all year long. This thirsty tree requires ample regular water and will not tolerate drought.

10. Ginkgo (Ginkgo biloba)

~ 401 Tennyson Avenue, 3 street trees

Also known as Maidenhair tree, it has a unique leaf shape and it turns a gorgeous yellow in the fall. Because the leaves fall nearly all at once, they create a carpet of color underneath the tree. Ginkgos have been around for a very long time. Some fossilized ginkgo leaves have been dated to 270 million years ago – the time when dinosaurs still roamed the earth.

11. English Hawthorn (Cratagus laevigata ‘Paul’s Scarlet’)

~ 350 Tennyson Avenue, 2 street trees on either side of the front walk

This small tree is native to the English midland forests. This cultivar, ‘Paul’s Scarlet,’ has been produced since 1858 and has become a favorite for parks and gardens. It produces rosy-pink flowers in the spring and red berries that persist into the fall.

12. Incense Cedar (Calocedrus decurrens)

~ 327 Tennyson Avenue, next to the sidewalk in the right front corner

Common in the Yosemite Valley floor, this native evergreen conifer is sometimes confused with the Coast Redwood because of its reddish brown bark. Initially slow growing, when established it can grow 2’ per year and will reach 75–90’.

13a. Giant Sequoia (Sequoiadendron giganteum)

~ 310 Tennyson Avenue, 3 trees in a cluster in the left side of the front yard

It looks like an incense cedar, but is closely related to the Coast Redwood. This is the largest tree and actually the largest living organism in the world; at higher altitudes massive trunks can reach a diameter of 30’. It is native to the western slopes of the Sierra Nevada.

13b. Deodar Cedar (Cedrus deodara)

~ 310 Tennyson Avenue, front yard near the corner of Bryant Street

Native to the Himalayas, this drought-tolerant tree is commonly planted throughout Europe and North America. It is distinguished from other cedars in the way that the ends of branches droop down. The needles are 1–1½” long, softer than on other cedars, and are bunched into clusters on the branches.

14. Mayten (Maytenus boaria)

~ 1750 Bryant Street, small tree right of the front door

This native of Chile has narrow 1–2” long light to medium green leaves. Its beautiful weeping form makes the Mayten a good smaller substitute for the Weeping Willow (Salix babylonica). Water deeply to reduce the likelihood of surface roots.

15a. Common Catalpa (Catalpa bignonioides)

~ 290 Lowell Avenue, 7 street trees on Bryant Street

The leaves are large, bold, and heart-shaped. In late spring, large clusters of trumpet-shaped flowers appear. The flowers, white with yellow markings and lavender spots, are followed by long, bean-shaped seed capsules that stay on the tree for a long time.

15b. Chinese Pistache (Pistacia chinensis)

~ 290 Lowell Avenue, front courtyard to the left of the front door

This deciduous tree has foot-long compound leaves composed of 10–16 narrow 2–4” long leaflets. Its fall foliage colors are stunning – scarlet, crimson, orange and yellow. The fruit on female trees is initially bright red, turning a dark blue. The seeds yield oil used in cooking, and in Asia the leaf buds are boiled and eaten. To avoid litter from fruits, plant the male variety ‘Keith Davies’.

16. Carob (Ceratonia siliqua)

~ 280 Lowell Avenue, right of the front gate in the left front corner

Densely covered with 2” oval, dark green leaflets, Carob trees have a thick trunk with rough brown bark. The thick, flat pods on female Carob trees take a full year to develop and contain seeds that are used as a chocolate substitute. This evergreen tree is extremely drought-tolerant.

17. Western Redbud (Cercis occidentalis)

~ 300 Lowell Avenue, 2 trees right of the driveway

This deciduous California native with almost-round leaves grows in the foothills below the 4,000’ level. As a shrub or small tree it reaches 10–18’ high and wide. In spring it has a stunning three-week display of magenta flowers.

18. Blue Spruce (Picea pungens ‘Glauca’)

~ 340 Lowell Avenue, just inside driveway gate on left

This American favorite is native to the Rocky Mountains at altitudes up to 10,000’. It is often found as a solitary tree on dry slopes or next to dry creek beds. Notice that the cones hang from the branches, unlike the Deodar Cedar, which has cones on the tops of the branches. In gardens it reaches 30–60’ and 25–35’ wide.

19. Black Locust (Robinia pseudoacacia)

~ 375 Coleridge Avenue, street tree on Waverley Street near the corner

Because emigrants brought seeds with them from the eastern U.S., Black Locust is now common everywhere in the West. Older specimens, such as this one, have deeply furrowed bark and are often hollow. It is a deciduous tree with oval leaflets arranged opposite each other, and the smaller woody branches typically have thorns. In the spring, many clusters of white flowers appear. This tree is highly invasive by root sprouting.

20. Flowering Crabapple (Malus x zumi ‘Calocarpa’)

~ 1550 Waverley Street, 2 street trees and 2 front yard trees

A small deciduous tree suited for many locations in the urban landscape. Most mature at 15–25’. Crabapples come in weeping and upright forms with flowers ranging from white to rosy pink and small fruits may or may not appear. The trunk often has an interesting form. ‘Robinson’ is a tough drought-tolerant selection, and ‘Echtemeyer’ is a small graceful weeper.

21a. Crape Myrtle (Lagerstroemia hybrid)

~ 1530 Waverley Street, 2 street trees on either side of the front walk

These deciduous trees have small leaves opposite each other on branches. In addition to their stunning bark and bright late summer flowers, Crape Myrtles provide beautiful fall color. To guarantee a tree resistant to powdery mildew chose one of the “Native American Tribe” cultivars. Good for small gardens and drought-tolerant.

21b. Flowering Dogwood (Cornus florida)

~ 1530 Waverley Street, 2 street trees and a tree at the right front corner of the house

A U.S. native, this small deciduous tree is suitable for smaller gardens. Its 2–4” oval leaves turn bright red in fall and it produces showy white bracts in springtime. Provide good drainage and regular water. Plant as an understory tree in partial shade, as leaf scorch can occur during the summer months when plants are located in a full sun exposure.

22. Coast Live Oak (Quercus agrifolia)

~ 410 Churchill Avenue, street tree at the corner of Waverley Street

This is an example of a tree fighting to survive in an unhealthy environment. Notice how the root crown is impacted by the sidewalk and asphalt. The soil compaction creates anaerobic (without air) conditions in the soil, which is favorable to root rot organisms. Not feasible here, the removal of some paving would improve the tree’s environment.

Symbols Legend

Trees protected by the City of Palo Alto tree ordinance

A permit is needed to remove or prune these trees.

Check the City of Palo Alto Tree Regulations.

Trees with low watering needs

These trees are best adapted to our climate and water availability.

Thirsty trees

These trees require frequent summer irrigation and will suffer from the drought cycle in our area.

Do not plant unless you are aware of a water source such as high water table or creek proximity.

Trees not recommended for planting

These trees are either invasive, do not perform well or create infrastructure or other problems.

Sign up for local tree news, events, volunteer opportunities, and more.

Sign Up

“It is worth any amount
of effort to be able to see
your house through
the arch of a tree.”

~ Thomas D. Church
Landscape Architect
and writer

Volunteer Learn