Siberian elm Ulmus pumila
IDENTIFICATION — Remember American elms? The leaves of this 50- to 70-ft.-tall, 30- to 50-ft.-wide woody weed look similar. However, they’re usually smaller and riddled by insects. In spring, before the leaves even open, you’ll spot clusters of pale-green flowers on the branches. Later, usually by early summer, large quantities of small papery disclike seeds begin to fall. They are spread by the wind, sprout and grow very quickly. Siberian elm trees have weak wood, so you’re constantly picking up the fallen twigs and branches.
FAVORITE CONDITIONS — You’ll find Siberian elm growing in full sun to part shade in moist to average soil.
CONTROL —?When the plant is a seedling, pull or dig it out of the ground. If it’s too large for this, spray the plant with a nonselective herbicide, such as Roundup® Poison Ivy & Tough Brush Killer Plus in spring or late summer. Or cut down the tree and dribble or brush on a systemic stump killer around the edges where the sap is flowing. It’s absorbed into the wood and kills the roots. Be careful, it can kill any plant it gets on.