Downy Mildew

Description:

Downy mildew affects roses throughout the U.S.

Symptoms:

Infection begins on young plant growth. Leaves develop dark purplish to dark brown spots. Symptoms may resemble burns caused by pesticide toxicity. Humid, cool conditions favor downy mildew infection.

Solutions:

If downy mildew has been a problem in the past, begin spraying with a copper soap when new spring growth emerges. Repeat every 7-10 days for as long as needed to control disease. Fixed copper is one of the oldest fungicides and bactericides used to control a wide range of plant diseases. We recommend Soap-Shield® Flowable Liquid Copper Fungicide.*

Soap-Shield may cause copper toxicity on some rose varieties. Copper toxicity appears as purple spots and is more likely to occur outdoors than in greenhouses.

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