Yellow Leaves with Dark Spots on Knockout Roses After Heavy Rain

Yellow Leaves with Dark Spots on Knockout Roses After Heavy Rain

Prolonged rain often causes temporary yellowing and spotting on lower leaves – not necessarily a serious disease. The excess water can also leach nutrients from the soil.

Immediate Actions

1. Remove yellowed leaves to improve air circulation.
2. Apply a handful of rose fertilizer around each plant to replace lost nutrients.
3. Ensure good drainage; avoid additional watering until soil dries.

When to Worry

If symptoms persist after dry weather returns, or if spots have feathery yellow halos (classic black spot), apply a fungicide. Knockouts are resilient and usually bounce back once sunshine returns.