Tree of Heaven

Description

Tree of Heaven is a deciduous tree native to Asia that was introduced to North America in the late 18th century. Known for its rapid growth and ability to thrive in diverse conditions, it is used in urban areas despite its invasive nature. This species is particularly noteworthy as being the preferred host for the invasive Spotted Lanternfly (Lycorma delicatula).

  • Scientific Name: Ailanthus altissima

  • Common Name(s): Tree of Heaven

  • French Name: Ailante glanduleux

  • Regulatory Status: While not listed as a noxious weed in the BC Weed Control Act, it is recognized as an invasive plant by the Canadian Food Inspection Agency (CFIA) and is targeted for regional containment and control. In Canada, tree of heaven can be found in British Columbia, Ontario, and Quebec.

Tree of heaven

© Sepp Schmid via iNaturalist.org, used under CC BY NC

Introduction and Spread

Originally introduced as an ornamental and street tree, its proliferation is supported by its tolerance to pollution and poor soil conditions. Its spread in North America and Europe was facilitated by its popularity in horticulture and its ability to disperse seeds over considerable distances through wind and water.

Distribution

From its native regions in northeast and central China and Taiwan, Tree of Heaven has become invasive across North America, Western Europe, South Africa, Australia, and New Zealand, thriving particularly in urban settings like parking lots, streets, and abandoned sites.

Habitat

The Tree of Heaven is often found in disturbed urban environments but can also invade natural forested areas and agricultural fields, adapting to a wide range of environmental conditions.

Identifying Features

  • Leaves: Pinnately compound, up to 1 meter long with 10-41 leaflets, each 5-15 cm long.

  • Flowers: Small, clustered in large panicles, blooming white to greenish-yellow in late spring.

  • Fruit: Samaras, 3-5 cm long, winged, turning from green to bright red.

  • Bark: Smooth on young trees, becoming rough and gray-brown with age.

Biology

  • Reproductive Strategies: Capable of sexual reproduction, producing up to 325,000 seeds annually, and asexual reproduction through vigorous root suckers and resprouting.

  • Growth: Grows rapidly, with new sprouts capable of extending several meters from the parent tree.

Impacts

Ecological

Tree of Heaven dominates sites by forming dense stands that outcompete native vegetation and releasing allelopathic chemicals that inhibit the growth of surrounding plants.

Economic

Its roots can damage urban infrastructure, including buildings, roads, and sewer systems.

Social

The plant’s odorous nature when crushed and its potential to cause allergic reactions in some people pose public health and comfort issues.

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What You Can Do

Plant Wise

Avoid planting non-native or invasive plant species, like tree of heaven, in your gardens. Our Grow Me Instead guides are great resources for choosing native alternatives for your yard and gardens!

1. Isler, J., Bugmann, H., Conedera, M. et al. Long-term dynamics of tree of heaven (Ailanthus altissima) in central European forests. Eur J Forest Res 142, 1149–1166 (2023). https://doi.org/10.1007/s10342-023-01582-9
2. Bauman, Jenise; Byrne, Caitlin; and Hiremath, Shiv, “Ailanthus altissima (Tree-of-Heaven) Interferes with Beneficial Symbionts with Negative Impacts on Oak Regeneration” (2013). Huxley College on the Peninsulas Publications. 10. https://cedar.wwu.edu/hcop_facpubs/10

Invasive Species Categories

Stop The Spread: Report Invasive Species

How to Prevent and Manage Invasive Species

The Impact of Invasive Species on Canada’s Ecosystems and Economy

Invasive Species Resources: Guides, Manuals, and Best Practices