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Western Sycamore
Platanus racemosa
About Western Sycamore (Platanus racemosa) Nurseries Show All Photos Western Sycamore is a species of plane tree known by several other common names, including California sycamore, California plane, and Aliso. It is native to California and Baja California, where it grows in canyons, floodplains, and along streams in several types of habitat. It is also planted as a landscape tree in its native range. This large tree grows to 35 meters in height, but is more commonly 20-25 meters, with a trunk diameter of up to one meter. A specimen on the campus of Stanford University has a trunk circumference of 10.5 feet. The trunk generally divides into two or more large trunks splitting into many branches. The bark is beautiful, with areas of white, pinkish gray and pale tan, with older bark becoming darker and peeling away. The leaves can be extremely large, up to 10 in. wide. The plant is deciduous, with leaves turning an attractive yellow and orangish brown in the fall. The rather plain-looking flowers are 1 in. spheres that becomes seed balls.

Western Sycamores are tough and easy to grow, but they need a lot of water. Plant by a stream or seep, or be prepared to give it plenty of supplementary water - 1x per week. Roots tend to go down not out if the plants are given sufficient water, so they are a good tree to plant near patios or in urban environments. It tolerates a wide variety of soils, and prefers to have its leaves in full sun. They grow quickly if given plenty of water, often growing to 30 feet in just five years.
Plant Description
Plant Type

Max. Height
20 - 115 ft (6.1 - 35.1 m)

Max. Width
50 ft (15.2 m)

Rounded, Upright Columnar


Growth Rate
Fast, Slow

Winter Deciduous

Flower Color
Yellow, Cream, Orange, Brown

Flowering Season
Spring, Winter

Native Status

Natural Setting
Site Type
Almost always found in wetland-riparian settings such as streamsides, canyon bottoms with more moisture below 4,000 ft. from northern Central Valley to coastal San Diego County and Baja. It is often found adjacent to drier habitats such as chaparral, valley grassland, mixed woodlands or evergreen forests


Elevation ?
-6' - 11310'

Annual Precip. ?
3.8" - 57.7"

Summer Precip. ?
0.15" - 2.31"

Coldest Month ?
24.6° F - 59.1° F

Hottest Month ?
45.5° F - 87.7° F

Humidity ?
0.47 vpd - 38.56 vpd

Soil Description
Tolerates sand and clay

Soil PH
5.0 - 8.0

Fast, Medium, Slow

Cold Tolerance(° F)
Tolerates cold to 10° F

Sunset Zones ?
1, 2, 3, 7, 8, 9, 11*, 14, 15, 16, 17, 18*, 19*, 20*, 21*, 22, 23, 24

Companion Plants
The large, deciduous leaves tend to bury small understory plants unless regular leaf removal is carried out. Use with larger shrubs or small trees that can tolerate additional water, such as Wild Rose (Rosa californica), Ninebark (Physocarpus capitatus), Mock-Orange (Philadelphus lewisii), willows (Salix species), and Mulefat (Baccharis salacifolia).

Wildlife Attracted
Important for Western Tiger Swallowtail butterfly and other butterflies, hummingbirds,

Landscaping Information
Ease of Care
Very Easy

Water Requirement ?
Moderate - High
Extremely Low
Very Low
Moderate - High

Moderately Popular

Max. Summer Water ?
No Summer Water
Keep moist

Deep Organic, Organic with Rocks

Pest Control
Susceptible to anthracnose fungus (leaf blight) which typically does not kill the tree but causes disfiguration of the leaves in mild cases and leaf loss in severe cases.

Propagation ?
Stratified seed.  For propagating by seed: 2-3 mos. stratification.

Common uses
Deer Resistant, Bird Gardens, Butterfly Gardens

Nursery Availability
Commonly Available

Other Names
Common Names
Aliso, California Plane, California Sycamore

Sources include: Wikipedia. All text shown in the "About" section of these pages is available under the Creative Commons Attribution-ShareAlike License. Plant observation data provided by the participants of the California Consortia of Herbaria, Sunset information provided by Jepson Flora Project. Propogation from seed information provided by the Santa Barbara Botanical Garden from "Seed Propagation of Native California Plants" by Dara E. Emery. Sources of plant photos include CalPhotos, Wikimedia Commons, and independent plant photographers who have agreed to share their images with Calscape. Other general sources of information include Calflora, CNPS Manual of Vegetation Online, Jepson Flora Project, Las Pilitas, Theodore Payne, Tree of Life, The Xerces Society, and information provided by CNPS volunteer editors, with special thanks to Don Rideout. Climate data used in creation of plant range maps is from PRISM Climate Group, Oregon State University, using 30 year (1981-2010) annual "normals" at an 800 meter spatial resolution.

Links:   Jepson eFlora Taxon Page  CalPhotos  Wikipedia  Calflora

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