Pronounciation: PLA-ten-us ox-ca-den-TAL-is
USDA 5 - 11
Landscape Use: Deciduous shade tree, parks and greenspaces. Not for use in narrow street medians of sidewalk planter strips.
Form & Character: Upright mushroom topped canopy, regular, mesic, heavenly white during winter..
Growth Habit: Woody, deciduous perennial tree, moderate to vigorous to 40 to 80 feet tall with nearly equal spread though mostly smaller and shorter lived in Phoenix because of heat stress.
Foliage/texture: "Maple-like" in shape, highly pubescent to tomentose large leaves that are are 3-5 lobed, lobes 1/4 to 1/5 as long as blade (smaller than other Platanus species), foliage often prematurely senesces in Phoenix. Tree trunk mostly smooth and white to cream colored and blotched, the trunk and branches are a nice winter accent in the eastern US; medium coarse texture.
Flowers & fruits: Flowers born on axillary meristems, visually insignificant; fruit mostly in pairs, bristly and rounded, litter on ground tough for the bare footed - OOuch!!
Seasonal color: Golden brown fall color is typical in temperate climates, but rarely occurs in Phoenix.
Temperature: Tolerant of winter cold, but sensitive to summer temperatures above 110oF. Premature foliar senescene in late summer in Phoenix is common.
Light: Full sun
Watering: American sycamore rarely looks good in Phoenix except for spring (new seasonal foliage) even with the obligatory regular, frequent irrigations.
Pruning: Like other smooth trunked trees, elevate canopy base, train vigorously as standard when young to avoid making large pruning cuts when tree matures. After transplanting, allow numerous small, short spur branches to grow on the lower trunks of immature trees for first few years in order to enhance trunk caliper and protect trunk from sunscald. Remove these spur branches as the tree's overarching and spreading canopy begins to consistently shade the tree's main trunk.
Propagation: Softwood or hardwood cuttings
Disease and pests: In Phoenix disease and pest problems are minor. Otherwise, spider mites, scale, anthracnose (Apiognomonia veneta syn. Gnomonia platani), and powdery mildew are more common problems of American sycamore when grown in more humid climates.
Additional comments: American sycamore is a bit of an oddity in Phoenix. It does not tolerate the Phoenix heat well and as such is not a 'tree of choice' when considering deciduous shade trees. A better choice is the Arizona mountain canyon native, Platanus wrightii, if sycamore is desired..