Lilac Leaf Curl After Bloom: Check for Waterlogging First

Lilac leaves turning dark, dry, and curling backward after flowering often signals root rot from poor drainage—not a foliar disease.

Simple Soil Test

Squeeze a handful of soil from the base. If water drips out, it’s too wet. Lilacs need well-drained soil.

If Soil Is Fine

Check for insects (borers, scale) or fungal cankers on stems. But start with drainage—fixing that often resolves the issue.