Saving a Wilting Petunia: Overwatering vs. Underwatering

A potted petunia with yellowing, hardening leaves likely suffers from overwatering leading to root rot. Petunias need to dry out between waterings.

Diagnosis and Rescue

1. Check soil moisture: if constantly wet, stop watering until surface feels dry.
2. Learn pot weight: heavy = wet; light = time to water.
3. If root rot suspected, cut back half the stems, let soil dry, then water with diluted fertilizer.
4. After recovery, prune a few stems every two weeks through August to promote bushy growth and more flowers.

Check for Mildew

If leaves show white or gray powder, it’s powdery mildew—a fungal disease. Discard the plant; treatment is rarely worth the effort for annuals.

With proper wet-dry cycles and light feeding, petunias bounce back quickly and bloom until frost.