American sycamore (Platanus occidentalis)
Species info:
Leaves: Alternate, simple, 3–8" wide; palmately lobed, resembling a maple but alternately arranged (key ID feature). Upper surface bright green and smooth; lower surface pale and fuzzy.
Leaflets: None (simple leaf).
Leaf Surface: Glabrous above; pubescent and softer beneath.
Bark: Brown on young stems; on mature trees the outer bark exfoliates in irregular plates, revealing striking smooth, creamy-white inner bark that creates a mottled appearance.
Flowers: Inconspicuous; male and female flowers occur separately on the same tree (monoecious).
Fruit: A single spherical achene ball per stalk (most often), 1–1½" diameter; fuzzy, brown, and persistent into winter. London planetree typically has two per stalk.
Twigs: Orange-brown, slender, zig-zag in form.
Botanical: Platanus occidentalis
Family: Platanaceae
Mature Height: 70–100+ feet (very large shade tree)
Canopy Spread: 60–80 feet with age; very wide-spreading crown
Foliage Type: Deciduous
Tree Shape: Broad, irregular, spreading crown; pyramidal when young, massive with age
Growth Rate: Medium to fast with irrigation
Flower: Not showy
Fruit: Can be messy
Fall Color: Typically dull yellow to brown
Water Use: High; performs best with consistent moisture or irrigation
Hardiness: Zones 4–7
Soil Preference: Prefers deep, moist, fertile soils; tolerates a wide range but performs poorly in dry, compacted conditions without irrigation
Sun Exposure: Full sun
Wildlife Value:
– Seeds eaten by finches, juncos, and other small birds
– Cavities in mature trunks provide habitat for owls, raccoons, and other wildlife
– Large leaves provide excellent shade
Pests/Pathogens: Anthracnose is the most notable issue; causes leaf blight, twig dieback, and early leaf drop, sycamore lace bug and powdery mildew occur but are rarely fatal in Colorado
Planting Recommendations: Recommended for most sites along the Front Range as it is vulnerable to exposure and has some concerns for cold hardiness
Information Sources:
Front Range Tree Recommendation List
Michael Dirr, Manual of Woody Landscape Plants
Michael Kuhns, Trees of Utah and the Intermountain West
