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.*
*NOTE:
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.