Borer Damage and Scale on Kwanzan and Weeping Cherry Trees

Borer Damage and Scale on Kwanzan and Weeping Cherry Trees

Amber resin (gummosis) oozing from the trunk or branches of cherry trees typically indicates borer activity—beetle or moth larvae tunneling beneath the bark. White, crusty deposits on bark are scale insects, which also weaken trees by sucking sap.

Integrated Approach

• Borers: Apply permethrin (Hi-Yield 38 Plus) as a trunk spray in spring before egg hatch. For active infestations, systemic imidacloprid (Bayer Tree & Shrub) or dinotefuran can kill larvae inside the tree.
• Scale: Apply dormant oil in late winter (below 80°F) to smother overwintering stages. Follow with a systemic for season-long control.
• Tree Health: Mulch, water during drought, and fertilize based on soil test to boost resistance.

Consult your county Extension office for precise timing and product recommendations in your area.