Invasive Alien Plant Species of Virginia Tree-of-Heaven (Ailanthus altissima (Miller) Swingle)

Description Tree-of-heaven is a small to medium-sized tree in the mostly tropical Quassia family. It has smooth gray bark. Leaves are compound, alternate, odd-pin- nate, with 11-25 lanceolate leaflets. Most leaflets have one to three course teeth near their base. Tree-of-heaven leaves may be confused with those of sumac or black walnut. Flowers occur in panicles at the ends of branches; male flowers produce a strong odor which has been described as “the smell of burnt peanut butter.” The leaves when crushed also produce this distinc- tive, offensive odor. Seeds are centered in a papery sheath called a samara. The samaras are slightly twisted or curled, and twirl as they fall to the ground. They can be borne on the wind great distances from the parent plant.

Habitat establish a taproot three months Tree-of-heaven establishes itself from germination. Thus they quickly readily on disturbed sites. These in- outrace many native plant species in Tree-of-Heaven (Ailanthus altissima) clude vacant lots of the inner city, competition for sunlight and space. as possible, preferably when the soil railroad embankments, highway Tree-of-heaven also produces a is moist to insure removal of the en- medians, fence rows and roadsides. toxin in its bark and leaves. As these tire taproot. Larger plants should be In naturally forested areas, distur- accumulate in the soil, the toxin in- cut; two cuttings a year may be nec- bance created by severe storms or hibits the growth of other plants. essary, once in the early growing insect infestations can open the way This toxin is so effective it is being season and once in the late growing for tree-of-heaven infestation. studied as a possible source for a season. Initially, this will not kill the natural herbicide. These factors Distribution plant; it will vigorously resprout combine to make tree-of-heaven a Tree-of-heaven is native to a region from the roots, but seed production very aggressive invasive plant able extending from China south to Aus- will be prevented and the plants will to displace native tree and herb spe- tralia. It was imported into the be lowered in stature. If continued cies. Furthermore, the root system United States in 1784 by a Philadel- over a period of several years, cut- is capable of doing damage to sew- phia gardener. In the western states ting during the growing season ers and foundations. it was brought over by Chinese im- stresses the plants and may eventu- migrants who use it for medicinal ally kill them. Control purposes. Due to its rapid growth Tree-of-heaven is very difficult to A glyphosate herbicide, either and prolific seed production, it remove once it has established a tap- sprayed onto the leaves or painted quickly escaped from cultivation. root. It has persisted in certain areas onto a freshly cut stump will kill the Threats despite cutting, burning and plant. However, to insure the herbi- One tree-of-heaven can produce up herbiciding. Therefore, seedlings cide gets into the root system, it is to 350,000 seeds in a year. Seedlings should be removed by hand as early best to apply this herbicide in the late

For more information, contact the Department of Conservation and Recreation or the Virginia Native Plant Society.

Virginia Native Plant Society P.O. Box 844, Annandale, VA 22030 1500 E. Main Street, Suite 312, Richmond, VA 23219 (804) 786-7951 Invasive Alien Plant Species of Vir ginia T ree-of-Heaven growing season while the plant is propriate concentrations, and the and Ailanthus glandulosa. The Nature translocating nutrients to its roots. effective method and timing of their Conservancy, San Francisco. Glyphosate herbicides are recom- application. Consult a natural re- Hu, S. 1979. Ailanthus. Arnoldia 39(2):29- mended because they are biodegrad- source specialist or agricultural ex- 50. able, breaking down into harmless tension agent for more information components on contact with the soil. before attempting herbicide control However, glyphosate is a nonselec- of tree-of-heaven. Illustration reprinted by permission from tive, systemic and will affect all The New Britton and Brown Illustrated green vegetation. To be safe and ef- References Flora of the Northeastern United States and Adjacent Canada, vol. 2, pg. 469, H. fective, herbicide use requires care- Hoshovsky, M. 1986. TNC Element Gleason, copyright 1952, The New York ful knowledge of the chemicals, ap- Stewardship Abstract: Ailanthus altissima Botanical Garden.

For more information, contact the Department of Conservation and Recreation or the Virginia Native Plant Society.

Virginia Native Plant Society P.O. Box 844, Annandale, VA 22030 1500 E. Main Street, Suite 312, Richmond, VA 23219 (804) 786-7951