Tree-of-heaven

Ailanthus altissima

Invader Images

    • Tree-of-heaven leaves are compound
      Tree-of-heaven leaves are compound
    • Tree-of-heaven fruit
      Tree-of-heaven fruit
    • Tree-of-heaven infestation
      Tree-of-heaven infestation
    • Tree-of-heaven leaves have gland on underside of the leaf
      Tree-of-heaven leaves have gland on underside of the leaf

Common Look-alikes

    • staghorn sumacStaghorn Sumac (Rhus hirta) has toothed leaf edges, and lacks the tell-tale glands that Tree-of-heaven have on the underside of the leaf
      Staghorn Sumac (Rhus hirta) has toothed leaf edges, and lacks the tell-tale glands that Tree-of-heaven have on the underside of the leaf

Identification

Appearance

This rapidly growing tree can reach a height of 80 feet, with up to a six-foot diameter trunk. Leaves are pinnately compound with 10 to 41 leaflets with smooth leaf margins. When crushed, the leaves and other plant parts have a rancid smell like cat urine or burnt peanut butter.

Foliage

Foliage is one of the best identifying characteristics for this species. The leaves are pinnately compound and 1-4 ft. (0.3-1.2 m) in length with 10-41 leaflets. Ailanthus altissima resembles native sumac and hickory species, but it is easily distinguished by the glandular, notched base on each leaflet.

Flowers

Species is dioecious and flowering occurs in early summer when large clusters of yellow flowers develop above the foliage.

Fruit

Fruit produced on female plants are tan to reddish, single winged and can be wind or water-dispersed. 

Biology

ECOLOGICAL THREAT

Ailanthus altissima forms dense, clonal thickets which displace native species and can rapidly invade fields, meadows, and harvested forests. This invasive tree species is extremely tolerant of poor soil conditions and can even grow in cement cracks. Ailanthus altissima is not shade tolerant, but easily invades disturbed forests or forest edges causing habitat damage. Introduced as an ornamental, it was widely planted in cities because of its ability to grow in poor conditions. Management and control efforts for this species continue across the United States at great economic cost. 

Although this majestic tall tree is called tree-of-heaven, it is regarded as an invasive species that is capable of displacing native trees, poisoning root systems, damaging sewer lines with its roots, and producing a sap that can cause heart imflammation.

ORIGIN

First introduced from its native China into the U. S. in 1751, it has since been planted throughout American cities because it is fast-growing, resistant to pollution, and provides ample shade. However, it is now considered quite invasive.

HABITAT

Forest, forest edges, shrublands, thickets, disturbed areas

LIFE CYCLE

Flowering occurs in early summer, when large clusters of yellowish flowers develop above the leaves, Fruit produced on the female trees are tan to reddish, single winged, papery seeds, called samaras. They may remain on the tree throughout late fall.

Management Options

This species is Quarantined: Class B Noxious Weed

MECHANICAL CONTROL

Elimination of this species is difficult and time-consuming, due to its abundant seed, high germination rate, and frequent root sprouts. Manual and Mechanical While young seedlings could be pulled or dug up, the chance of getting all root fragments is difficult and can lead to re-sprouts. Seedlings can be confused with root suckers, which would be nearly impossible to remove effectively by hand. Cutting is not recommended, as the trees will send up large numbers of root sprouts and suckers, creating a bigger problem than before.

CHEMICAL CONTROL

Chemical The most effective way to treat ailanthus is with herbicides. Foliar application of triclopyr or glyphosate, mixed with water and a non-ionic surfactant, is effective on smaller trees when applied between June and late August. For larger trees, application of triclopyr or glyphosate with the basal bark, hack and squirt, or injection should work effectively. Cut-stump herbicide application, however, may encourage root suckering. Application rates may vary—see the references below for more specific information. Follow-up monitoring and treatment are very important. Regardless of the control method used, treated areas should be checked one or more times a year.

 

**Be careful not to damage or kill nearby native plants when conducting management work. And when using herbicides, always follow the instructions on the label.**