The Box Elder (Acer negundo) is a native North American maple often considered a nuisance due to its characteristics. It grows rapidly but has brittle, weak wood that breaks easily in high winds or from ice load, creating a maintenance hazard. Female trees are prolific self-seeders, producing large quantities of winged samaras that result in numerous volunteer saplings. Additionally, the Box Elder hosts the Box Elder bug (Boisea trivittata), which becomes a significant household pest when seeking shelter to overwinter.
Physical Removal: Cutting Down and Eliminating the Stump
Immediate removal involves felling the tree and eliminating the root crown. For large specimens, especially those near structures or power lines, hiring a certified arborist is necessary. A professional ensures the tree is safely removed without property damage.
After felling, addressing the stump is crucial, as Acer negundo is notorious for vigorous regrowth through root suckering. Cutting the trunk level with the ground will result in multiple, fast-growing shoots emerging from the stump and surrounding roots. The most effective physical method to prevent suckering is complete stump removal, typically performed with a stump grinder.
Stump grinding machines mechanically chew the stump down several inches below the soil line, destroying the root collar where regenerative buds are concentrated. Grinding 6 to 12 inches deep is usually sufficient to eliminate immediate regrowth, though new shoots may emerge from lateral roots further away. Alternatively, the stump can be manually dug out, a labor-intensive process requiring tools to sever and remove major roots.
Applying Herbicides for Tree Death
When physical removal is impractical due to size, location, or cost, chemical treatments effectively kill the root system. The recommended approach is the cut-surface treatment, which involves applying a concentrated systemic herbicide directly into the tree’s active vascular tissue. This ensures the chemical is translocated throughout the root system.
One common cut-surface technique is the “hack-and-squirt” method. A hatchet is used to create downward-angled cuts, or “frills,” around the trunk’s circumference. A concentrated herbicide, such as glyphosate (20% or higher) or triclopyr, is immediately squirted into each cut, contacting the living cambium layer beneath the bark. Application must be done quickly, ideally within 5 to 30 minutes of cutting, before the tree seals the wound.
The cut-stump treatment involves felling the tree and painting or spraying concentrated herbicide onto the freshly cut surface. For stumps larger than three inches, focus application only on the outer ring of sapwood and the cambium, as the central heartwood is non-living. The optimal time for both treatments is late summer or early fall, aligning with when the tree actively moves sugars and the systemic herbicide down to the roots for storage.
Preventing Ongoing Growth and Controlling Seedlings
After the primary tree is gone, managing new growth requires sustained effort. The most common recurrence is the emergence of aggressive root suckers from the extensive, shallow root system. These suckers, which can grow several feet in a single season, should be spot-treated with a systemic herbicide rather than cut, as cutting only stimulates more growth.
Suckers can be treated by applying a ready-to-use triclopyr-based brush killer directly to the leaves or by using a cut-stem treatment on the fresh cut. Repeatedly mowing suckers in a lawn area can eventually deplete the root system’s stored energy, though this may take several years.
Box Elder trees produce prolific seeds that germinate easily, creating numerous volunteer saplings. Small seedlings should be removed by hand-pulling or digging to ensure the entire root is extracted before establishment. Larger saplings can be controlled by a foliar spray of a broadleaf herbicide, taking care to avoid overspray onto desirable nearby plants. All cut wood and vegetative debris should be disposed of properly according to local regulations to prevent re-sprouting or disease transmission.