Tree of Heaven

Growing up to 25m tall, the tree of Heaven’s flowers are visible in spring and are a pale green-white colour. Tree of Heaven forms dense stands, meaning surrounding plant growth is constricted. It also may facilitate the establishment of other pest plant species.

Description

Leaves are up to 40 x 70cm and compound.
Flowers are pale green-white and visible in spring.
Seeds are winged and papery, maturing in autumn.
Seeds are dispersed by wind and water. Vegetative spread from suckering.
Habitats include forest gaps and margins, wastelands, roadsides, urban areas, agricultural areas, riparian margins, urban areas, and disturbed habitats.

What you need to know

Forms dense stands and suppresses surrounding plant growth (allelopathic). May alter nutrient cycling regimes and facilitate the establishment of pest plant species.

Management approach

Tree of Heaven is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest, including unwanted organisms, cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, or multiplied, communicated, released, or caused to be released, or otherwise spread.

Consider removing this invasive species from your property and consult your local council for appropriate disposal. Consider lower-risk alternatives for your garden, such as native plants.

Control

Site management

Follow up treated areas three times per year. Encourage natural regeneration of native plants or replant treated areas where possible after two to three treatments to establish dense ground cover and minimise reinvasion.

Physical control

Dig or pull out.

Plant parts requiring disposal: Seeds.

Contact your local council for appropriate disposal locations.

Chemical control

No qualifications: Cut stump and paste freshly cut base of stems with metsulfuron gel.

Basic Growsafe certified: Cut the stump and spray the freshly cut base with 1g metsulfuron-methyl per 1L of water.

Certified handler/experienced agrichemical user: Drill and inject trees with 10g metsulfuron-methyl per 1L of water if safe to do so. Drill 18mm holes (tangentially angled downwards) in a spiral up the trunk.

For 50mm stems drill one hole. For 100mm stems drill two holes. For larger stems drill holes 150mm apart. Foliar spray seedlings with 5g metsulfuron-methyl per 10L of water and 20ml penetrant.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.