Controlling Spreading Sumac Near a Vegetable Garden

Frank has sumac encroaching from a hillside into his vegetable garden, with new shoots popping up among the crops. Sumac spreads aggressively via underground rhizomes, making eradication challenging.

Physical Barriers

• Steel edging: Install 4-inch-deep steel landscape edging along the garden border, flush with the soil surface. This can slow but not completely stop rhizome spread.
• Buried timbers: For a more robust barrier, dig a trench 1 foot deep and install two stacked 5×6 pressure-treated timbers along the garden edge. This significantly impedes rhizome movement.

Cultural & Chemical Controls

• Persistent cutting: Repeatedly cut shoots at ground level to exhaust root reserves. This requires diligence over several seasons.
• Herbicide application: Apply a systemic herbicide (like glyphosate) to freshly cut stumps or foliage on the sumac side of the barrier. Shield desirable plants. Follow label instructions carefully.
• Root removal: In extreme cases, excavate the garden perimeter to remove rhizomes, then install a deep barrier.

Recommendation

Combine a deep timber barrier with regular cutting on the garden side. Avoid herbicides within the vegetable bed. Over time, this integrated approach will reduce sumac pressure.