Sycamore (Platanus species) is a deciduous tree with ten species worldwide. Five Platanus species grow in Mexico, two grow in the southwestern U.S., and one grows in the eastern U.S. American sycamore, Platanus occidentalis, is the eastern species and is common throughout South Carolina. It grows well in USDA Hardiness Zones 4 to 9. Even though it is adapted to all areas of the state, it is most commonly found in bottomlands, riparian areas, and along rivers and streams.
Sycamore is often grown as a shade tree in managed areas. The patterned bark on mature trees is extremely eye-catching. London planetree (Platanus x hispanica) is a hybrid, also common in South Carolina and hardy in USDA Zones 5-8. This species is almost exclusively planted in urban areas, while American sycamore is typically found in natural areas.
American sycamore (Platanus occidentalis)
The American sycamore is also called buttonwood or buttonball.
Mature Height/Spread: American sycamore is a massive tree that can grow 75 to 100 feet tall with a similar or greater spread. Under ideal conditions, it can grow to 175 feet high with a trunk diameter of 10 to 14 feet. It has a pyramidal form when young but develops a spreading, rounded, and irregular crown with age. Keep in mind if incorporating this species into a yard, along a road, or in any other managed area that sycamores are large trees that require ample space.
Growth Rate: The growth rate is moderate to rapid (2 feet per year), and sycamore has a moderate to long life span (50 to over 200 years).
Ornamental Features: American sycamore is highly valued for its stately form and massive size and are valued as shade trees. Under ideal conditions, it is one of the most massive tree species in eastern North America. Though American sycamore usually develops one strong central trunk, occasionally, double leaders (i.e., two trunks that are close in diameter) will form.
While handsome in all seasons, the cream- to olive-colored exfoliating bark is exceptional when contrasted with the dark bark of other trees in a woodland setting during the winter. The lower trunk bark is red to gray-brown and scaly, while the upper bark peels off in large flakes exposing smooth, lighter-colored (white to creamy white) bark underneath.
The large leaves are alternately arranged, simple, and palmately veined and vary in size, even on the same tree. Each leaf has three to five lobes with coarsely toothed margins and small leafy stipules at nodes encircling the twigs. The leaves are cream-colored and wooly when they emerge in the spring. At maturity, they are large, medium to dark green, and wooly only along the veins on the lower side. Fall color is yellow-brown. The fruit consists of seeds clustered into a round 1-inch diameter ball hanging from a long, flexible stalk through most of the winter. They usually hang individually but sometimes hang in pairs.
Landscape Use: Sycamores are too big for most home properties and are primarily used for parks, large-scale landscapes, or naturalized stream plantings. Although they have been used extensively as street trees and can withstand difficult city conditions, they can be high maintenance. Consider the leaf and twig litter, disease problems, and aggressive roots when choosing this tree for high-traffic pedestrian and vehicular areas.
Sycamore prefers deep, moist, rich soils but will grow in marginal soil with low oxygen and high pH. Sycamore prefers full sun or light shade locations and tolerates moderate drought.
Prune drooping branches on trees located near vehicular or pedestrian traffic. Eliminate the occasional double leader to promote a single trunk. Prune healthy wood in the winter. Remove dead, damaged, and diseased wood anytime to reduce the incidence of disease.
Problems: The most severe disease is anthracnose, which can be a serious problem during wet, cool springs. Cankers, bacterial leaf scorch, powdery mildew, and leaf spot are other possible disease problems. Aphids, sycamore lace bugs, scales, and borers are common insect pests. For more information about sycamore problems, see HGIC 2011, Sycamore Diseases & Insect Pests.
Sycamore does best in naturalized or open areas near streams and rivers or sites where litter and aggressive roots are not an issue.
Avoid planting sycamore near well-tended lawns, pavement, and buildings since they create leaf, fruit, and twig litter. While not a problem when growing along streambanks or out-of-the-way places, maintenance becomes an issue for turf areas or near pedestrian or vehicular traffic.
Cultivars: No cultivar selections are commercially available. If purchasing American sycamore from a nursery, try to select trees grown from local native parents when possible.
London planetree (Platanus x hispanica)
London planetree is a hybrid cross between P. occidentalis and P. orientalis. It is sometimes listed as P. x acerifolia.
Mature Height/Spread: London planetree grows 70 to 100 feet tall, 65 to 80 feet wide, and can reach 120 feet in height under ideal conditions.
Growth Rate: The growth rate is moderate to rapid (2 feet per year) and has a moderate to long life span.
Ornamental Features: London planetree is like American sycamore, except it has a smaller spread, duller colored bark (though still showy), and fruit hanging in pairs.
Landscape Use: London planetree does well in places like parks or open, managed areas with ample space to develop. Plant at least six feet from the sidewalk or curb as its aggressive roots can raise sidewalks. The tree’s roots and dense shade typically prevent healthy turfgrass growth under its canopy.
London planetree prefers deep, rich, moist, well-drained soils but will tolerate poor soil. It grows in either high or low-pH soils. Although London planetree prefers moist soils, it tolerates moderate drought. It prefers sun or very light shade.
Problems: London planetree suffers many of the same disease and insect problems as American sycamore. Canker stain can be a severe disease. Powdery mildew and anthracnose can be problems, but some cultivars are somewhat resistant to these two diseases. Disease resistance means that infections are few, do not progress very far, or do not occur. Like American sycamore, aggressive roots, litter, and poor turf growth beneath the canopy are other concerns.
- ‘Bloodgood’ is somewhat resistant to anthracnose and powdery mildew.
- ‘Columbia’ and ‘Liberty’ are reportedly more resistant (not immune) to powdery mildew and eastern strains of anthracnose.
- ‘Morton Circle’ Exclamation!® has a narrow pyramidal habit with a moderate growth rate and shows resistance to anthracnose.
- ‘Suttneri’ is an unusual selection with variegated leaves and very white bark.
Note: Foliar chemical treatments may be impractical for large trees. Therefore, disease and insect control may require insecticide or fungicide injections.
Originally published 06/99