Pronounciation: PLA-ten-us RYE-tee-i
Landscape Use: Shade tree, urban parks and green spaces, large patio gardens, commercial, large spaces, lawn tree, mesic landscape designs, native desert wetland restoration.
Form & Character: Arizona sycamore is an upright, rugged shade tree that is stiff and informal, lacking symmetry.
Growth Habit: Woody deciduous perennial tree, moderately upright, open and irregular to 50 feet tall with less than equal spread. In Phoenix, Arizona sycamore growth rate is highly positively dependent on irrigation intensity and landscape context. When mature, Arizona sycamore tree trunks are stately.
Foliage/texture: Simple leaves with 3 to 5 deep lobes, 4 to 6 inches wide, pubescent when yuong to often scabrous with age, margins entire or sometimes dentate, trunk mostly smooth light gray to blotchy white, mottled and shredding; medium coarse texture.
Flowers & fruits: Monoecious, imperfect male and female flowers in small, reddish clusters in axillary meristems during April-May just after new foliage emergence in the spring, thus flowers are born under the foliar canopy and are not a landscape amenity, inconspicuous. Fruits significant, smooth stalks with 2 to 4 rounded tan fuzzy fruits, 1 to 1.5 inches in diameter, seed wind dispersed during winter (in contrast, P. racemosa has bristled fruit heads without stalks).
Seasonal color: Arizona sycamore can have a subtle, pleasing golden brown foliar color in fall in its native habitat, although during most years this foliar accent usually fails to be manifest in the lower desert landscapes. During winter months, the exposed whitish trunk and branches of all syamore species is an accent when trees are leafless.
Temperature: Tolerant of all but the most extreme heat associated with expansive impervious surface covers and buildings.
Light: Full sun
Watering: Arizona sycamore is an obligate phreatophyte that needs at least access to ground water in its native habitat to thrive, thus we consider it to be a mesic landscape tree that does best in Phoenix with regular applications of supplemental irrigation.
Pruning: Do not prune for several years after planting into the landscape to encourage transplant establishment and trunk caliper, then elevate canopy base slowly over time to desired canopy height. Young trees rarely needs staking.
Propagation: Seed or softwood or hardwood cuttings.
Disease and pests: Compared to California sycamore, Arizona sycamore is relatively anthracnose resistant. Or maybe it's just the dry air of Arizona?
Additional comments: Arizona sycamore is similar in form, habit, and texture to P. racemosa (California sycamore showing fall color in a coastal canyon outside of Los Angeles). Some taxonomist consider Arizona sycamore a geographic cline of California sycamore. In summary, Arizona sycamore is a handsome tree with a mostly multiple-trunked, asymmetric form and habit that is often arduous to train into a symmetrical, standard form. Sycamores are generally thought to be tough trees that can tolerate polluted urban conditions.