How to Grow Tree of Heaven
Ailanthus altissima
Tree of Heaven is one of the world's most invasive trees — fast-growing, tough, and nearly impossible to eradicate once established. Check local regulations before planting; it is banned or restricted in several European countries. Plant in full sun in almost any soil. Very little care is needed once established, but root suckers must be removed regularly throughout the growing season. Never cut the trunk without treating the stump with systemic herbicide immediately, as cutting stimulates years of aggressive suckering. Keep well away from buildings, foundations, drains, and paths.
Yearly Lifecycle
Care Essentials
Rarely needs feeding. Thrives in poor soil without fertiliser. If growth is very slow in year one, a light balanced fertiliser in spring is sufficient.
Watch For
- Verticillium wilt
- Honey fungus
- Root suckers spreading aggressively
Care Requirements
Light
Full sun
Requires full sun and thrives in open, sunny positions. Tolerates partial shade but grows more vigorously in full light. Ideal for exposed urban sites.
Watering
Drought-tolerant once established
Water regularly in the first growing season to establish roots. Once established, extremely drought-tolerant and rarely needs supplemental watering even in hot, dry summers.
Fertilizing
No feeding required
Grows vigorously in poor, unfertilised soil. Applying fertiliser encourages even faster and harder-to-manage growth. Avoid feeding entirely unless the tree is showing signs of stress in its first year.
Pruning
Minimal; dormant season only, with herbicide readiness
If pruning is needed for shape, do so between November and February when fully dormant. Any cut stimulates root suckering — have glyphosate or triclopyr ready to treat the stump if removal is the goal.
Spacing
Minimum 10 m from buildings and services
Plant at least 10 m from foundations, walls, drains, sewer lines, and paved surfaces. The root system is aggressive and will spread far wider than the canopy. Allow 10 m between trees.
Support
Not required
Fast growth means the trunk thickens rapidly and the tree is self-supporting from an early age. No staking needed except in very exposed windy sites in year one.
Growing Tips
Check legality first
Tree of Heaven is banned or restricted in Austria, Switzerland, Czech Republic, Hungary, and other European countries. Verify your local regulations before planting or allowing it to grow. Where invasive status applies, removal may be legally required.
Invasive warning — keep away from structures
The root system is extremely aggressive. Plant at least 10 m from buildings, foundations, drains, sewer lines, and paved areas. Roots actively seek moisture and will exploit any crack.
Never cut without a herbicide plan
Cutting the tree stimulates vigorous suckering from the roots and cut stump. For intended removal, apply a glyphosate-based or triclopyr herbicide to the freshly cut stump immediately after cutting. Without treatment, cutting alone guarantees years of regrowth.
Remove suckers promptly and regularly
Root suckers appear throughout spring and summer, often many metres from the parent tree. Pull or cut suckers when young — leaving them even briefly allows them to develop their own root systems and become harder to remove.
Unpleasant smell from foliage
Leaves, flowers, and bark emit a strong, rancid-smelling odour when bruised or cut. This is particularly noticeable during flowering in early summer. Wear gloves when handling cut material.
Urban and poor-soil tolerance
Tolerates compacted urban soil, pollution, drought, rubble, and neglect better than almost any other tree. This toughness is precisely what makes it so difficult to control in cities.
