Box elder Acer negundo
IDENTIFICATION — Box elder leaves have three lobed leaflets that are somewhat pointed. The stems are smooth green to dark red with a white waxy coating that you can rub off with your fingers. Click to see a foliage detail.
A single or multi-stemmed tree that grows up to 75-ft.-tall, box elder is not good to have in your garden. Winged seeds can sprout almost anywhere and new trees can also sprout from the shallow roots, which make it hard to grow anything nearby. In addition, its weak wood breaks easily in storms.
FAVORITE CONDITIONS — Box elder is not picky. Any place in full sun to part shade with moist, even wet soil is fine. It readily adapts to almost any conditions except deep shade or very dry soil.
CONTROL — Pull seedlings if you spot them when they’re young enough. This is the best method in areas where you can’t dig or spray, such as in ground cover beds.
Spray young sprouts in open, mulched areas with nonselective herbicides, such as Roundup® Poison Ivy & Tough Brush Killer Plus. Always follow the label directions, but you usually apply these products to actively growing weeds in spring or summer.
Digging is the preferred method in beds where spraying a herbicide would be risky for the other plants. Plus, unlike spraying actively growing weeds, digging lets you get rid of box elder any time you can push the shovel into the soil.
Once box elder gets too big to dig, you’ll need to use a saw to remove it. Then 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.