Controlling Aggressive Box Elder Suckers: Herbicide Strategy for Root Elimination

The Persistent Sprouting Problem

Box elder (Acer negundo) sends up vigorous suckers 10-20 feet in a single season. Cutting them only stimulates more growth from the extensive root system.

Two Scenarios, Two Solutions

Scenario A: You want the tree gone entirely
Apply concentrated glyphosate (Roundup) directly to freshly cut sucker stumps or foliar-spray the leaves. The herbicide translocates to the roots, killing the entire system. Critical: Avoid drift onto desirable plants. Apply on calm days with a shielded sprayer or paintbrush.

Scenario B: You want to keep the tree but stop suckering
Never use herbicide. It will kill the parent tree. The only safe method is persistent manual removal—cut suckers below soil level repeatedly. Mulch heavily to suppress light. Accept that some suckering is natural for this species.

Application Tips for Scenario A

• Cut suckers, immediately paint undiluted glyphosate on cut surfaces
• Or spray active growth when leaves are fully expanded
• Repeat as new shoots emerge—typically 2-3 treatments needed
• Fall application often works best (carbohydrate translocation to roots)

Safety First

Glyphosate is non-selective. Protect valuable plants with cardboard shields. Wear gloves, eye protection. Follow all label instructions. Consider hiring a licensed applicator for large areas.