Tree of Heaven

Native to central China and Taiwan, it can tolerate poor soils and can grow in disturbed urban areas where it sprouts up in alleys, sidewalks, parking lots and streets. In rural areas, tree of heaven can grow in fields, along roadsides, lakeshores and forest edges.  Its preferred habitat is sun to partial shade on forest edges, gardens and empty fields. Tree of heaven is intolerant of flooding and deep shade. It is widespread throughout British Columbia.  

• Tree of heaven is the preferred host of the spotted lanternfly, an invasive insect that is regulated in Canada because of its threat to the grape, fruit tree and forestry industries, as well as the environment
• Tree of heaven is a preferred host of the brown marmorated stink bug, an invasive insect that is regulated in Canada because of its threat to the grape, fruit tree and forestry industries, as well as the environment
• Prolific seed producer and can successfully outcompete native vegetation 
• Can develop dense thickets of cloned trees 
• Chemicals contained in the leaves, bark, roots and seeds can suppress the growth and germination of surrounding plants (i.e. allelopathic effect)
• The aggressive root system can cause damage to sewers, foundations and sidewalks  
• In some people, tree of heaven pollen causes allergic reactions and exposure to sap or plant parts can cause skin irritation

• Do not trade or grow tree of heaven   
• Regularly patrol your property for  invasive trees  and immediately control or remove  new seedlings  
• Cooperate with adjacent landowners and encourage them to prevent  invasive tree  spread
• Immediately re-vegetate disturbed, bare soils with a suitable seed mixture that provides dense, early colonization to prevent  invasion  
• Do not move contaminated soils to a new area 

• Seedlings can be hand-pulled or dug out when the soils are moist
• Young trees (trunk diameter 8 cm or less) can be pulled out using a tree wrench; ensure the entire root is removed
• Mowing and brush-cutting can suppress trees, but are only effective if re-sprouts are continually cut throughout the growing season for multiple consecutive years; re-sprouts can be treated with herbicide
• Girdling can help to provide control; in the spring when trees are actively growing, manually cut away bark and cambial tissues around the trunk as close to the ground as possible using an axe
• Cut down large trees, ideally before seeds mature, and apply herbicide to the stump to prevent re-growth; re-cut sprouts and apply herbicide each growing season
• Chipping is an effective means of disposal for limbs and trunks
• Chemical control is also an option; before applying herbicides, read the label for full use and precautionary instructions
• For further information on the selection and application of chemicals to protect your crop, contact AgriService BC at 1-888-221-7141 or email AgriServiceBC@gov.bc.ca
• A mite has been identified as a promising biological control agent (natural insect enemy) for tree of heaven and is currently being researched in North America; studies have found significant damage to seedlings and new spring growth, indicating that this mite is sufficiently host-specific

For additional information on invasive trees of the Okanagan-Similkameen, check out this factsheet which provides identification, biology, and best management tips: Invasive Tree Factsheet