Tree of Heaven

Common Name: Tree of Heaven 
Scientific Name: Ailanthus altissima (Mill.) Swingle 
Synonyms: Chinese sumac, stinking sumac, stink tree, tree-of-heaven

Legal Status

Prohibited Eradicate

All above and below ground parts of the plant must be destroyed. Additionally, no transportation, propagation, or sale of this plant is allowed. Failure to comply may result in an enforcement action by the county or local municipality.

Background

Tree of heaven was brought to the U.S. in the late 1700s as an ornamental shade tree from China, Taiwan, and Vietnam. Today this tree is found in most of the continental U.S. and Hawaii.

Description

• A deciduous tree that can reach 80 feet in height. Twigs are light brown.
• Plants are dioecious, meaning male and female plant parts are on different plants. 
• Leaves are large (1-4 feet long), alternate, and compound with 10-40 smaller leaflets. Individual leaflets are 3-5 inches long, with smooth margins and two lobes at the base. 
• Flowers are small, yellowish green, and arranged in large, showy clusters at the ends of the leaves.
• Fruit are flat, twisted samaras that hang in long clusters.
• Bark on mature trees is textured and gray.
• Seedlings start displaying pinnately compound leaves early in their development.
• When crushed, leaves and all plant parts give a strong, offensive odor.
• Twigs have V or heart-shaped leaf scars, and when the twigs are broken, the pith is spongy.
• Fast growing, horizontal roots form a wide-spreading system that sends up new sprouts up to 90 feet from the parent stem.

Habitat

Thrives in areas of disturbance and in a wide range of soil types and conditions, including drought. It grows best in full sun and is fairly intolerant of shade and saturated soils. It is known as an adaptable and pollution-tolerant tree for urban settings and can grow in tight rooting spaces where other trees may not be able to grow. It is generally more common in disturbed urban and rural areas, such as roadsides and fence rows. In natural areas, it can be found on floodplains and other disturbed sites, open woodlands, and rock outcrops. 

Means of spread and distribution

Female plants are prolific seed producers and a single female tree may produce up to 325,000 seeds per year. It also spreads aggressively through vegetative means, in response to above-ground cutting or root breaking. Root fragments found in infested soil may start new populations if brought to a new area.

Impact

In urban areas, it can cause damage to sewers, pavement, and building foundations. Impacts to agriculture include being the primary host for spotted lanternfly, an invasive sap sucking insect causing problems in the eastern United States. Environmental impacts include the ability to release allelopathic chemicals helping it outcompete and displace native species. It releases allelopathic chemicals into the soil which is toxic to other species, and this helps it to establish and spread quickly without competition.

Prevention and management

• Do not purchase and/or plant tree of heaven.
• Cutting or mowing are ineffective because these actions stimulate tree of heaven to produce large amounts of stump sprouts and root suckers.
• Cut stump herbicide applications are ineffective.
• A foliar herbicide treatment in mid- to -late summer can be effective.
• Basal bark herbicide applications can be effective.
• Hand pulling seedlings may be effective when soil is moist, and the entire root system is removed. Small root fragments can generate new shoots.
• Repeated treatments and monitoring will be necessary to successfully eradicate tree of heaven.