Blackening Rose Buds: Rose Midge vs. Frost Damage on Mr. Lincoln Roses

Two Distinct Causes

Rose Midge: Tiny fly lays eggs at bud base; larvae tunnel in, causing buds to blacken and fail. Look for a minute hole at the base of affected buds. Control with systemic insecticide (e.g., acephate) applied when buds first form.

Frost Damage: 'Mr. Lincoln' is marginally hardy. A late spring freeze can kill developing buds, turning them black. No treatment; protect with frost cloth if a freeze is forecast.

How to Tell

If buds show a tiny entry hole, it's midge. If blackening follows a cold night and buds are intact, it's frost. Both can occur in the same season.