tree of heaven (Alianthus altissima)

Species info:

Leaves: Alternate, pinnately compound leaves with 10–41 leaflets. Leaves emerge bronze to purple and mature to dark green. Each leaflet typically has one or more glandular teeth near the base.

Leaflets: Lanceolate to ovate with smooth margins except for basal lobes containing scent glands.

Leaf Surface: Smooth and soft-textured; emits a strong odor when crushed.

Twigs: Thick, stout twigs with large leaf scars; light brown to gray.

Bark: Smooth and gray on young trees; becoming slightly fissured and darker with age.

Flowers: Dioecious (male and female flowers on separate trees). Male flowers produce a strong odor often compared to rancid peanut butter; female flowers are largely odorless.

Fruit: Clusters of papery winged samaras; reddish to tan; persist into winter and disperse readily by wind.

Botanical: Alianthus altissima

Family: Simaroubaceae

Mature Height: Typically 40–60 feet

Canopy Spread: 30–40 feet

Foliage Type: Deciduous

Tree Shape: Upright, spreading; often irregular due to aggressive suckering

Flowers: Inconspicuous

Fruit: Prominent

Fall Color: Unremarkable, yellowish brown.

Water Use: Very low once established.

Hardiness: USDA Zones 4-8

Soil Preference: Prefers moist, well-drained soils but thrives in compacted, disturbed, polluted, nutrient-poor, and dry soils

Wildlife Value: Limited native wildlife benefit; contributes to invasive insect spread

Pests and pathogens: Susceptible to Verticillium wilt; serves as a host for the invasive spotted lanternfly.

Notable Traits: Extremely tolerant of pollution, drought, heat, and poor soil. Aggressive roots systems that sucker to form dense colonies, making it very difficult to eradicate once established.

Planting recommendation: Do not plant. Listed as a noxious weed (List C) in Colorado.

Information Sources:

• Michael Dirr, Manual of Woody Landscape Plants (University of Georgia, 1990)