How to spot it

Large, greasy-looking gray-green to dark brown blotches on leaves and stems, with white fuzz underneath in damp weather. Fruit gets firm, greasy brown patches. It spreads in cool, wet weather.

What it does

It can kill whole plants in days and blows for miles on the wind. Potato tubers rot in the ground and in storage.

What to do now

• Pull infected plants right away, bag them, and put them in the trash, not the compost.
• Tell your neighbors and your county extension office: they track outbreaks.
• Sprays (copper and others) only protect healthy plants before it arrives; they don't cure sick ones.

Keep it away next time

• Plant certified seed potatoes, and never save potatoes from sick plants.
• Pull volunteer potatoes and tomatoes that come up on their own.
• Grow resistant varieties (such as Mountain Magic, Iron Lady, or Defiant tomatoes).

Helpful supplies

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Plants it affects

See also