Tree of heaven (Ailanthus altissima), is a perennial, relatively short-lived deciduous tree, originally from China.
The tree grows up to 70’ tall with up to 80’ in crown width and 6’ in trunk diameter. It is highly adaptable and can grow under limiting or harsh conditions, including soils that are saline, nutrient poor or highly compacted. It will also grow in areas affected by heat, drought, or pollution and has been troublesome in urban landscapes and woodland.
Reproduction is mostly sexual by seed, but new plants are also produced asexually from root sprouts. The species is dioecious with female trees producing clusters of persistent, one-seeded, winged fruit and male trees producing groups of flowers that smell like burnt peanuts. One female tree can produce 325,000 seeds or more annually, a large portion of which are viable, but not long lived, as seeds do not typically persist for more than two years.
Leaves are pinnate-compound with dark green, broadly lanceolate leaflets, margins entirely with teeth or lobes at the base; light green veins and whitish green underneath with glandular red dots near their lobes. Bark is light brown to pale gray, rough with fissures on trunk, and fast-growing, as young sprouts grow as much as 10 to 15 feet in a year.
The plant grows along roadsides, railways, fencerows, woodland edges, forest openings, or in riparian zones. Its aggressive root system can impact pavement and foundations, the wood is weak and breaks easily, and infestations crowd out native species. The plant has also helped advance the spread of the spotted lanternfly, an invasive insect also originally from China.
There are few occurrences of this species documented in Colorado. View the known North American Distribution Map. If you are aware of infestations that are not represented, please report your sighting. Register for an EDDMapS account, then select "Report Sightings". Please include photos with your submissions.