Japanese Beetles and Powdery Mildew on Florida Roses

Two Common Rose Problems in Orlando

Roses in central Florida face distinct challenges: Japanese beetles skeletonize flowers, while powdery mildew distorts new growth.

Japanese Beetle Control

With only a few plants, non-chemical methods work well:

• Morning shake-and-drown – Beetles feed at night and rest on plants by early morning. Shake bushes over a bucket of soapy water before 7 AM.
• Physical barrier – Cover plants with fine netting (bridal veil fabric) during the 4–6 week peak feeding period.

Powdery Mildew Treatment

Curling, stunted new leaves with a whitish cast indicate powdery mildew, favored by cool nights and warm days.

• Baking soda spray – 1 tablespoon baking soda + 1 quart water; spray daily until new growth is clean.
• Fungicide option – Rose fungicides containing sulfur, neem oil, or potassium bicarbonate also control mildew.

Cultural Prevention

Space plants for airflow, water at soil level (not overhead), and avoid excessive nitrogen fertilizer, which promotes succulent, mildew-prone growth.