This month’s tree spotlight is the American sycamore (Platanus occidentalis). The American sycamore is native to much of the eastern United States, including Vermont. It grows well in wet conditions on the edges of streams and lakes, and small depressions with slow drainage. It is a large tree growing 75 to 100 feet tall with equal crown spread, so it should be planted with plenty of room to grow. It grows well in alkaline soils and is somewhat salt tolerant. As sycamores mature they can grow hollow, this hollow provides habitat for wildlife, such as bears, and many birds. The seeds provide food for birds, weasels, beavers, and squirrels.
The sycamore has had a long history in the United States. There is a record of George Washington measuring a 13-foot diameter old sycamore in Ohio. The hollows of old sycamores were used to house livestock, such as cows, horses, and pigs, and even families would shelter in the hollows while they built their houses (Peattie, 2013). The wood is very difficult to split and so pioneers used the wood that was already hollowed out to make wheels, barrels for grain. Sycamore was also used in the construction of early railroad cars, Saratoga trunks, piano and organ cases, and phonograph boxes. Unfortunately, many large sycamores were cut down for the resources they provided. The largest known sycamore in Ohio today has a diameter of 11.5 feet.
The big tree program is a national program that tracks and records the biggest trees of each species around the country. The Vermont big tree program is based on the national program; its scoring system comprises 3 measurements: height, crown width, and circumference at breast height. The current champion American sycamore is in Townshend, Vermont. The last time it was measured in 2009, its height was 115 feet, it had an average crown spread of 28 feet, and its circumference at breast height was 16 feet 10 inches a diameter of 5.5 feet.
Common names: American Sycamore, American planetree, buttonwood, and buttonball-tree
Height: 75-100 feet
Hardiness Zone: 4 - 9
Leaf: Leaves grow alternately, are 4 - 8 inches wide, with 3 - 5 lobes, edges can be coarsely toothed.
Flowers: monoecious, which means it has both male and female reproductive parts; both male and female flowers are small and appear in dense round clusters. Appearing in May.
Fruit: A sphere formed of achenes, which are small dry one-seeded fruit (as you would see in a sunflower) borne on a 3 - 6-inch stalk. The seeds are tiny, winged, and ½ inch long maturing in September or October and often remaining on the tree over winter, breaking up and falling the next spring.
Twig: brown, gray, orange
Bark: tan-gray exterior bark peels to reveal white and olive-green bark beneath
Habitat: Tolerant of wet soil conditions, grows on the edge of streams and lakes and small depressions with slow drainage, as well as floodplains and wetlands. Grows best in open spaces, should not be planted as a street tree.
A Natural History of North American Trees by Donald Culross Peattie
5538520-Steven Katovich, USDA Forest Service, Bugwood.org
5191080-Allen Bridgman, South Carolina Department of Natural Resources, Bugwood.org
American Sycamore in Shelburne; Lee Krohn Photography