Siberian elm trees (Ulmus pumila) were originally brought to North America in the nineteenth century because they are fast-growing and hardy, and they continue to be grown and planted because they are resistant to Dutch elm disease. However, Siberian elm trees produce large amounts of seeds that grow aggressively, crowding out native plants in prairies and along waterways. Girdling it the most effective way to kill a Siberian elm tree, since the trunk will resprout for several years if you simply cut it down. Girdling trees prevents water and nutrients from moving from the roots to the limbs of the tree.
Plan to girdle the Siberian elm tree in spring or summer, when the sap is flowing and the tree is actively growing.
Use an ax, hatchet, chainsaw or hand saw to make an incision all the way around the trunk of the tree within about 3 feet of the base. The cut should go through the bark and the cambium, a spongy layer just under the bark, but should not penetrate much into the heart wood of the tree. On smaller Siberian elm trees, the cut should be about one-half inch deep, and on larger trees it should be up to 2 inches deep.
Make a similar incision just above or below the first cut. On small trees, the two cuts can be 2 inches apart, while on larger trees they should be 6 to 8 inches apart.
Peel off the section bark and cambium layer between the two cuts with a pry bar. It should pop off without much difficulty.
Consider applying glyphosate herbicide to the exposed part of the tree to hasten its demise. Girdled Siberian elm trees without herbicide will slowly die within one to two years, while trees treated with herbicide will die within the first year. Herbicide-treated trees are also less likely to put out new sprouts.
Check on the girdled tree periodically. Remove any bark that grows in the girdle and cut back any sprouts.