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TREE-OF-HEAVEN
(Ailanthus altissima)
PLANT DESCRIPTION
Tree-of-heaven is a rapidly growing,
rapidly spreading invasive tree
species. It usually grows as a
single-stemmed tree, but can also
be found growing in large, dense
colonies. Tree-of-heaven easily
reproduces by seed and root
sprouting. Mature trees can reach
heights of 60–75 feet.
LEAF: Large, pinnately-compound
leaves are alternately arranged on
branches. Leaflets are oval shaped with
a pointed tip and a smooth margin. Each
compound leaf contains 11–25 leaflets.
STEM: Stems are smooth and gray with tan furrows. Stems
are stout with inconspicuous naked buds. Wood is fragile and
easily broken. Broken stems have a strong odor reminiscent of
bad peanut butter.
FLOWER: Showy green to cream-colored flowers are born at the ends of
branches in erect clusters.
FRUIT/SEED REPRODUCTION: Seeds with papery wings are produced
at the ends of branches and later in the season become showy red before
dropping and being dispersed by wind. Tree-of-heaven trees can produce
seeds after only three years and a single tree can produce thousands of
seeds.
WHY IT IS A PROBLEM: Tree-of-heaven can create obstructions for
signs, roadways, and bridges. Tree-of-heaven not only rapidly regrows after
mechanical removal, but it also produces root sprouts and leads to a higher
per acre density if cutting without using herbicides. It also is an abundant
seed producer that can spread far distances and germinate in poor soils.
WHERE TO FIND:
Tree-of-heaven prefers dry soil and full
sun. It can easily take over disturbed
areas with poor soil. It is typically found
on slopes after clearing or grading.
CONTROL METHODS:
MECHANICAL: Mechanical removal is
difficult or dangerous on steep slopes
or in disturbed areas. Do not remove
without herbicide use unless immediate
clearance is needed.
CHEMICAL: Make basal bark
applications during the dormant
season or cut stump treatment to
tree-of-heaven stems under 6 inches
in diameter using an oil-based product
containing triclopyr mixed in oil. Foliar
applications can be made to younger
trees under 20 feet in height.
CULTURAL: Plant desirable vegetation
on slopes to provide competition
and reduce tree-of-heaven seed
germination.
RECOMMENDATION SUMMARY:
Tree-of-heaven should be controlled
while young before it can produce
seeds and before it reaches a size that
would require mechanical removal.
Manual removal promotes root
sprouting and leads to a higher density
per acre after cutting.
perennial
