This non-native Asian imported tree will rapidly grow to 70 to 100 feet in height and produces an open canopy. Broken stems smell of rancid peanut butter, and male trees reportedly smell worse than females.
The leaves turn only slightly yellow in fall before dropping but the 1.5-inch-long, yellow to red/brown, winged fruits which follow the blossoms will persist on the tree in dense clusters throughout the fall and into the winter months and are quite attractive but sprout easily and are messy.
Scientific name: Ailanthus altissima
Pronunciation: ay-LANTH-us al-TISS-sim-muh
Common name(s): Ailanthus, Tree-of-Heaven, Chinese sumac, stinking shumac
USDA hardiness zones: 5 through 8a
Origin: non-native from Asia.
Uses: reclamation plant
Availability: Grown in small quantities by small nurseries.
Tree-of-Heaven performs best in full sun on well drained, moist soil but this is a tree that will survive almost anywhere, under any cultural conditions - smoke, dust, hot, cold, wet, or dry. It has been known to appear in cracks of pavement or even trash piles, and it will survive where no other trees will grow (see photo). If well cared for, this tree can persist for a long time. Large specimens are known to grow trunks up to five feet in diameter.
Leaf: alternate arrangement, pinnately compound, leaflet margins ciliate, leaflet shape is ovate, leaflet veins are pinnate, leaves are deciduous, leaflet blades 4 to 8 inches long, leaf color is green, there is little to no fall color
Flower: Flower color is green and the flowering characteristics are showy and spring flowering.
Bark: The bark almost looks like the skin of a melon called a cantaloupe.
These dry, hard fruits are orange to yellow and from 1 to 3 inches in length. The shape of the fruit is elongated. Ailanthus fruit does not attract wildlife and can cause significant litter. The fruit is persistent on the tree and quite showy after fall.
Ailanthus is a prolific seeder, scattering up to 325,000 windblown seeds per tree each year. Tree-of-Heaven also spreads by suckering. It protects its territory by secreting toxins that suppress competing plants.
What the Experts Say!:
Dr. Mike Dirr, Professor of Horticulture, University of Georgia:
"The tree that grows in Brooklyn could be none other than this species. Tough, persistent, and durable to a fault,it has few redeeming landscape features."
Edward Sibley Barnard, Author, "New York City Trees":
"Biologists trying to keep the ailanthus from overwhelming native trees in urban parks and preserves have had only limited success. Despite their efforts, the ailanthus is here to stay."
"A Tree Grows in Brooklyn":
The Tree-of-Heaven was used as the major inspirational theme in Betty Smith's novel "A Tree Grows in Brooklyn". The metaphor she used was that the ailanthus' obvious persistence was like her book's characters aspirations to a better life.
Little did she know that this plant is actually capable of widespread destruction of urban property in the form of damaged building foundations and sidewalks. That is literally the reverse of the metaphor expressed in the book.
The Tree-of-Heaven was introduced into the United States by a gardener in Philadelphia, PA, in 1784. The Asian tree was initially promoted as a host tree for moth silk production. It rapidly spread because of it's ability to grow quickly under adverse conditions. It also produces poisonous "ailanthene" in bark and leaves that helps limit competition.
It now has wide distribution in the United States, occurring in forty-two states, from Maine to Florida and west to California. It grows stout and tall to about 100 feet with a "fern-like" compound leaf that may be 2 to 4 feet long.
Tree-of-Heaven can't handle deep shade and is most commonly found along fence rows, roadsides, and waste areas. It can grow in nearly any environment that is relatively sunny. It can pose a serious threat to natural areas recently opened to sunlight. It has been found growing up to two air miles from the nearest seed source.