The Enemy: Chinese Elm (Ulmus parifola)

STRATEGY: This perennial invading tree can grow to a height of 50 feet and can have a foliage diameter of 60 feet. It has small green serrated leaves that have a thick cuticle. The small flowers produce thousands of winged seeds that are carried by the wind. This tree also has a loose flaky bark. Originally brought here as a landscape tree, it has now evolved to more of an invasive weed. Many horticulturists are recommending people to remove the tree at once or at least not plant any more trees as they are quite a burden to most.

ATTACK: This tree produces thousands of small seeds that float in the air and deposit themselves in areas such as bird baths, drain systems, and in beautiful landscapes. The hardy roots have been known to penetrate septic drains, lift sidewalks and driveways, ruin ditch and canal banks, and displace or shadow desirable vegetation. The tree can carry Dutch elm disease but it itself can be resistant to the disease itself. It will get slime flux that makes the tree look like it has a runny nose.

DEFENSE: Pulling the tree from the ground when it is young is very effective. Once the tree reaches maturity one can cut it down and treat the stump with a herbicide such as Garlon, impazipyr, or glyphosate. The treatment must be done immediately after the tree has been cut to its final stage. Waiting 15 minutes will reduce the amount of herbicide that can get into the stump for complete control. Read the product label but the products are generally used undiluted. One can also take the herbicide and spray directly into a hatchet or ax mark which leaves a dead tree for nesting and protection for wildlife.

To learn more, call Bonneville County Weed Superintendent Jeffrey Pettingill at 208-529-1397 or email