Elm family (Ulmaceae)
Habit: Siberian elm is said to be the hardiest of all elms. That’s not true. It is a fast growing deciduous tree that will reach a height of 50-70 feet with a round crown of slender, spreading branches. The bark is rough, gray or brown, and shallowly furrowed at maturity. Twigs are nearly hairless with small, blunt buds. The small, smooth, dark green-toothed leaves are about 1-21⁄2 inches long wide, and pointed at the tip. Small green spring flowers lack petals and occur in drooping clusters of 2 to 5. After flowering, a single seed forms in the center of each smooth, flattened, circular, 1/2-inch wide fruit. It reproduces by seed.
Culture: Tolerates a wide range of growing conditions. It can be found in wet and dry soils, grasslands, roadsides, and pastures. Native Origin: Northern China, eastern Siberia, Manchuria and Korea.
Problems: Elm leaf beetle is a constant problem.
Notes: Dry to mesic (middle moisture) prairies and stream banks are vulnerable to Siberian elm invasion. Thickets of seedlings soon form around seed-producing trees, bare ground areas, animal and insect mounds and other disturbed areas. Wind carries seed to distant areas where new colonies can form. This tough exotic survives under conditions not easily tolerated by other species, allowing it to take advantage of open ground and resources otherwise used by native plants. Fast growing seedlings of Siberian elm quickly overtake native vegetation, especially shade intolerant species. This often leads to invasion by additional weedy species, compounding the problem.
Advice: Don’t plant.