Summer Pruning Dogwoods: Borer Risk and Wound Treatment

A homeowner needs to prune dogwoods (Cornus florida) in summer for mowing clearance. Asks about borer risk and wound treatment.

Ideal pruning time: Winter (dormant)—borers (dogwood borer, Synanthedon scitula) are inactive. Summer pruning creates wounds that attract egg-laying females.

If summer pruning is unavoidable:

• Prune flush to branch collar—no stubs.
• Apply borer spray to wounds: chlorpyrifos (Dursban) or endosulfan (Thiodan) Note: many residential uses cancelled; check current labels. Modern alternatives: permethrin, bifenthrin, or emamectin benzoate trunk injection (professional).
• Use pruning paint only if borer pressure is high—modern research shows paint can trap moisture and delay compartmentalization.

Better strategy: Mark branches now; prune in winter. For mowing, consider mulch beds or groundcovers under dogwoods to eliminate close mowing.