Invasive Amur Corktree

Introduced as an ornamental tree, the shade-tolerant Amur Corktree (Phellodendron amurense) invades forests and prevents native trees from growing. Download our Amur corktree infosheet.

History of Amur Corktree

Amur corktree was initially introduced from Asia to North America in the 1850s as an ornamental and is still being used as an ornamental tree today.

Regulation of Amur Corktree

Amur corktree is not regulated in Illinois. It is regulated in Maine, Maryland, Massachusetts, New York, New Hampshire, and Wisconsin and is on known invasive lists in Indiana, Kentucky, Maryland, New Jersey, and Pennsylvania.


A map showing the midwest and where the Amur Corktree can be found
Amur Corktree Damage

Amur corktree invades forest edges and canopy gaps, affects tree regeneration in forests, and displaces native vegetation. Amur corktree are shade-tolerant and can persist in the understory of closed-canopy forests. They have been increasingly found invading disturbed forests across Illinois and the eastern U.S., especially near urban and suburban areas where it has been introduced as an ornamental and street tree. Birds consume the fruits and spread seeds to new areas.

Amur Corktree
Amur Corktree
How to Identify the Amur Corktree

Amur corktree is a deciduous tree growing up to 50 feet in height with corky bark that is spongy to the touch, especially on more mature trees. The leaves of Amur corktree are opposite and pinnately compound with 5 to 13 leaflets and entire margins. The fruits of Amur corktree are drupes 0.25-0.5 inches in diameter that are initially green and turn to black at maturity around June or July. Another identifying characteristic is the bright yellow inner bark that can be revealed by scraping the outer bark.

peeling bark of amur corktree
Bark peeling from amur corktree
amur corktree
Management of Amur Corktree

Use alternative native species in landscaping that benefit native wildlife and are not invasive.

How to Control Amur Corktree

  • Mechanical: Small seedlings may be hand-pulled, especially in moist soils.
  • Chemical:  Always read and follow the herbicide label before initiating treatment. If seeds are present on the plant, take care not to spread them during control.
    • Leaves can be treated with a 5% v/v triclopyr amine or 2% v/v glyphosate solution while actively growing.
    • Basal Bark: For smaller plants less than 4 inches diameter, a basal bark application may be effective. Apply a triclopyr ester formulation at a 20% to 25% v/v rate, mixed with basal oil, to the lowest 15 inches of the stem.
    • Cut Stump: Resprouts vigorously if herbicide is not applied to cut stems. Apply triclopyr amine in water or ester in oil at a 20 to 25% v/v rate or glyphosate at a 50 to 100% v/v rate in water within 10 minutes of cutting.

For more information, explore Management of Invasive Plants and Pests of Illinois.

amur corktree bark
Resources on Amur Corktree