Self-Guided Tree Walk: Palo Verde

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The Palo Verde Tree Walk begins in front of Palo Verde Elementary School, 3450 Louis Road.

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1a. Evergreen Pear (Pyrus kawakamii)

~ Palo Verde Elementary School, row of 3 trees to the right of the main entry into the school

From late winter through early spring, this tree has an abundance of white flowers, and later bears a fruit that is extremely small and tasteless. This species is susceptible to several diseases; fire blight and bacterial leaf spot. Most trees in this area show some evidence of leaf diseases.

1b. Persian Ironwood (Parrotia persica)

~ Left of the main entry into the school

This tree was planted by Canopy in 2013 as are a number of young trees throughout the campus. Native to Northern Iran, it has a dramatic display of color in autumn when the leaves transition from a golden yellow to orange to rosy pink then scarlet. The dark red flowers appear in late winter on bare stems. 

1c. Valley Oak (Quercus lobata)

~ 3 trees along the street parking in front of the school

No other native California oak matches the sheer majesty of a mature Valley Oak. They, along with the Coast Live Oak, were the predominant native trees in the Santa Clara Valley hundreds of years ago. Landscape irrigation within the root zone of native oaks can cause a fungus to develop that often leads to the demise of the tree.

1d. Modesto Ash (Fraxinus velutina ‘Modesto’)

~ 6 trees around the front lawn of the school

These large deciduous trees are the most common street tree on this block. In the 16th century, ash keys, the single-winged seeds with a papery wing, were used to ward off witches and serpents. From 1940 through the 1960s this was one of the most popular street trees in California, but has fallen out of favor due to diseases and parasitic mistletoe infestations. 

2a. Autumn Purple Ash (Fraxinus americana ‘Autumn Purple’)

~ 3435 Louis Road, 2 trees close to the sidewalk

For streets with aging Modesto Ash trees, the City of Palo Alto is now planting this variety. Unlike other ash trees, this one is seedless, which eliminates the litter of ash keys, a winged seed, found under the Modesto Ashes. The list of street trees planted by the City of Palo Alto is evolving as they learn more about the various species. 

2b. Scotch Pine (Pinus sylvestris)

~ 3435 Louis Road, center of front yard

The Scotch Pine started out in Northeast France over 9,000 years ago and spread across the British Isles. Today, it is an important forestry tree, and is cultivated around the world for its pulp and timber products.

3. Flowering Dogwood (Cornus florida ‘Cherokee Daybreak’)

~ 3455 Louis Road, center of front yard

This small, delicate tree has variegated foliage. The bright green center of each leaf is surrounded by an uneven white edge tinged with pink. Pure white “flowers” are actually white bracts, or modified leaves, surrounding a cluster of small non-showy flowers in the center that are followed by bright scarlet berry-like fruits in late summer. 

4. Hollywood Juniper (Juniperus chinensis ‘Torulosa’)

~ 3465 Louis Road, near the corner of Greer Road, against a fence

With its rich green foliage and twisted, irregularly-shaped branches, this tree often takes an unusual windswept form. It was a popular plant when the homes in this area were built in the late 1940s and many examples can be seen in this neighborhood.

5. Red Oak (Quercus rubra)

~ 3498 Janice Way, right of the driveway near the sidewalk

A native of northeastern United States and a deciduous tree. In mild winter climates, like Palo Alto, it holds onto its brown leaves well into winter. People often assume it’s a dead tree but it’s not. This tree prefers deep monthly watering. 

6. London Plane Tree (Platanus x acerifolia)

~ 3492 Janice Way, left front corner

The most widely-planted street tree in the world and the second-most in Palo Alto (Magnolia grandiflora holds the #1 spot), this tree is very tolerant of atmospheric pollution and root compaction commonly found in cities. The fungal disease, anthracnose, attacks older varieties but newer hybrids are now resistant to the disease.

7a. Shamel Ash (Fraxinus uhdei)

~ 3487 Janice Way, right of the driveway

This fast-growing tree develops a majestic canopy over city streets when planted as a street tree, as you can find on this block. In its first ten years it can grow to 30 ft. and may eventually reach 80 ft. The roots are very aggressive, and it is not a good choice for a small yard.

7b. Olive (Olea europaea)

~ 3487 Janice Way, left side of the driveway

Olive trees were introduced to the California Mission gardens by Franciscan missionaries for the production of olive oil. Olive trees thrive in our climate as an evergreen, drought-tolerant tree with edible fruit, but only after the fruit undergoes a lengthy leaching process that removes the bitterness. Fruitless varieties are available and should be considered when planting near a sidewalk or decking to prevent fruit stains.

8. Yew Pine (Podocarpus macrophyllus)

~ 3433 Janice Way, near the front door

Not a pine at all, Yew Pine is usually pruned as a hedge or formal column. This specimen is unusual in that it has been permitted to grow in its natural shape with branches to the ground. It is native to southern Japan and China. 

9a. Chinese Pistache (Pistacia chinensis)

~ 3427 Janice Way, right of the driveway near the sidewalk

The Pistache grows best in full sun and is often planted as a street tree in urban environments. Native to China, it is often seen in classical Chinese garden designs. Fall leaves turn a brilliant and almost neon red, orange, and yellow. The fruit on the female trees (which is not edible) begins a bright red then turns dark blue. 

9b. White Mulberry (Morus alba)

~ 3427 Janice Way, in the center of the left property line

This is a fruitless cultivar of the White Mulberry, a tree native to China. It grows fairly rapidly to a height of 30 ft. with a canopy spread of 50 ft. casting a dense shade underneath. Due to heavy surface roots they are nearly always found in lawns. The leaves are the preferred food of the silkworm. 

10. Japanese Maple (Acer palmatum)

~ 3407 Greer Road, near the front door

Maple trees range in size from dwarf shrubs to tall trees. The fruit, called a samara, has a pair of winged segments with a seed in the middle that is perfectly weighted to spin like a helicopter blade. When choosing one for your garden, shop in the autumn months to see what their fall color is. Best planted in part shade since leaf scorch is common when planted in the full sun.

11. Chinese Elm (Ulmus parvifolia)

~ 3415 Greer Road, on the cul-de-sac side in front of the fence

A common street tree with many different cultivars, this particular tree has long weeping branches that nearly reach to the ground. The tree’s interesting bark is “exfoliating,” which means that small patches of the bark regularly peel off as a mechanism for the tree to eliminate toxins from air pollution. Elms are easily recognized by their leaves: one side of the leaf is longer than the other where it emerges from the stem.

12. Deodar Cedar (Cedrus deodara)

~ 3427 Greer Road, on the corner

Highly scented and native to the Himalaya where it is used as incense. This tree has been allowed to grow in its natural form: its lower branches touch the ground and then sweep up. The cones of Deodar Cedars sit on top of the branches, pointing upward. They take a year to mature and disintegrate while still on the branches. 

13. Blue Oak (Quercus douglasii)

~ 3439 Greer Road, in front of house along sidewalk

This is a true native tree as it is found only in California, in 39 of the state’s 58 counties. It is a landmark species that grows on the foothills that border hot interior valleys. The common name “blue oak” comes from the dark blue-green tint of its leaves that is most visible in the fall.

14a. Fuyu Persimmon (Diospyros kaki ‘Fuyu’)

~ 3458 Greer Road, center of front yard

Fuyu Persimmon is one of the best fruit trees for ornamental use. A small deciduous tree with large, glossy leaves that turn neon colors in the fall, it requires very low maintenance and the best part is the tasty fruit. Fuyu Persimmons have a shape similar to tomatoes and are best eaten when crisp like apples, unlike the Hachiya Persimmon that are ripe and edible only when gooey soft. 

14b. Fig Tree (Ficus carica)

~ 3458 Greer Road, left side of front yard

This tree with edible fruit is originally from the Middle East and western Asia. It grows fairly fast to 15-30 ft. tall and wide and normally has low branches. They can be grown in containers or espaliered along a fence or wall. Home grown figs do not need pollinating and most varieties bear crops twice a year. 

15a. Kousa Dogwood (Cornus kousa)

~ 3468 Greer Road, 2 trees left and right of driveway nearest garage

Native to Japan and Korea, this small tree has white “flowers” on the tops of branches in late spring. Like all dogwoods, what appear to be flower petals are actually bracts – petal-like modified leaves – that surround the inconspicuous true flowers. Red fruits that look like raspberries stick up from the branches in the summer. 

15b. Marina Madrone (Arbutus ‘Marina’)

~ 3468 Greer Road, left of driveway near the sidewalk

This tree resembles the Strawberry Tree (Arbutus unedo)  but has larger leaves and rosy pink  flowers in the fall. The red bark is a unique characteristic. The red fruit is edible, but mealy, and best left for the birds.

15c. Eastern Redbud (Cercis canadensis ‘Forest Pansy’)

~ 3468 Greer Road, right of the driveway near the sidewalk and 2 trees on the far left

This eastern United States native can be temperamental to grow, but the reward is stunning. In spring the redbud flowers emerge directly from the woody part of the trunk and larger branches. This is called cauliflory and is found mostly in tropical trees. Eastern Redbuds prefer shade and need ample water.

16. Carolina Laurel Cherry (Prunus caroliniana)

~ 3469 Greer Road, center of front yard near the sidewalk

This evergreen tree is native to the coastal regions of the southern United States and Texas. It grows as a tall, dense shrub or a small tree. Birds eat the fruit and bees love the pollen, but for humans the seeds, twigs, and leaves are high in toxins and should never be consumed.

17. Little-leaf Linden (Tilia cordata)

~ 3475 Greer Road, left front corner

Known as a lime tree in England, it has nothing to do with the citrus limes we’re familiar with. The leaves are dark green above and silver below which have a beautiful effect when fluttering in the wind. Aromatic flowers bloom in July. Locally, the Tilia cordata often suffers from aphid infestations, a better choice for a lawn or street tree is the Tilia tomentosa or Silver Linden. 

The tree prefers moist, well drained soil and does not do well in soils with high salinity.

18. Coast Redwood (Sequoia sempervirens)

~ 3481 Greer Road, 2 trees in front yard

The Coast Redwood is America’s tallest tree and lives to well over 1,000 years. In Palo Alto, the iconic Coast Redwood named El Palo Alto is that old. Coast Redwoods were heavily logged to help rebuild San Francisco after the 1906 earthquake. Although redwoods are protected by Palo Alto city ordinances, they are no longer considered suitable for planting in the valley floor due to their excessive water requirements and poor drought tolerance. 

19. Strawberry Tree (Arbutus unedo)

~ 3487 Greer Road, against the house

Despite its common name, there is no relationship with the delicious fruit found at the supermarket. It is edible though, especially for birds who love the fruit and bees the pollen. Originally found centuries ago in the Mediterranean region, it was included on Thomas Jefferson’s Monticello plant list in 1778. This is a very popular ornamental tree in California. 

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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.

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