Houseplant Diseases

Downy Mildew (Houseplants)

Downy Mildew (Houseplants)
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Each of the many fungi causing downy mildew attack a narrow range of hosts. Spread by wind, rain, and infected seeds, these fungi all require wet conditions, and most must also have cool temperatures (the exception is downy mildew of cucurbits, which can germinate at temperatures as high as 90┬░F).

Target: Many plants, including, English ivy, Boston Fern, snap-dragons, pansies, roses, marigolds, strawberries, grapes, and most vegetables.

Damage: Leaves show gray, white, or purplish fuzz on their undersides, yellow blotches on the top surfaces.

Control: Fungicides

Notes: Keep foliage as dry as possible.