WSU Extension


Geranium : Botrytis leaf spot and blossom blight
(revision date: 4/23/2014)

Botrytis is a fungus which thrives under mild environmental conditions. Brown, water-soaked areas appear on leaves and petals. The spots soon dry out and become covered with gray-brown masses of fungal growth. Flowers wilt and drop. Brown leaf lesions often result after petals drop on leaves. Stock plants may show a stem blight.
Management Options

Non-Chemical Management
  • An integrated strategy combining environmental management and cultural practices will best manage this disease.
  • Remove and burn infected leaves.
  • Increase spacing between plants.
  • Water at base of plants and/or with drip irrigation, do not wet foliage.
Select non-chemical management options as your first choice!

Chemical Management

Disease should be managed with cultural controls.

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Caption: Botrytis blight damage on geranium flower
Photo by: R.S. Byther
Caption: Botrytis blight damage on geranium leaf
Photo by: R.S. Byther