Home and Landscape

Brown Rot

  • Monilinia spp.
Updated: 09/2025

Blossoms on plants infected with Monilinia brown and wither. Dead blossoms often cling to twigs for a long time. Sunken, brown areas may develop around twigs at the base of infected flowers, causing leaves at the tips of twigs to shrivel up. Brown, sticky droplets of gum may exude from the base of dead flowers and the bark of infected twigs. Velvety gray or tan tufts of spores are formed on diseased blossoms or twig cankers. Brown or tan spots spread rapidly over the fruit surface and produce spores.

Life cycle

Solutions

Prompt removal and destruction of fruit mummies and diseased plant parts prevents the buildup of brown rot inoculum and helps keep rot below damaging levels. Prune trees to allow good ventilation. Furrow irrigate or use low-angle sprinklers to avoid wetting blossoms, foliage, and fruit. Plant varieties that are least susceptible; check with your local nurseryman. If you have had problems in the past, applications of copper-containing fungicides or synthetic fungicides such as myclobutanil at pink bud stage can help avoid serious losses. Additional applications when fruit starts to color may be needed if rainy weather persists. Do not apply copper compounds after bloom.

Foliage damage showing dried up leaves with rotted fruit; Ventura Co., . Credit: Jack Kelly Clark, UC IPM
Infected shoots. Credit: Jack Kelly Clark, UC IPM
Dead blossoms on twig hanging from branch that is exuding gum; Butte Co. Credit: Jack Kelly Clark, UC IPM
Droplets of gum. Credit: Jack Kelly Clark, UC IPM
Fruit damage Credit: Jack Kelly Clark, UC IPM
Brown rot on peach. Credit: Jack Kelly Clark, UC IPM
Prematurely ripened prune with brown tufts of sporulation; Butte Co. Credit: Jack Kelly Clark, UC IPM
Spores on prune. Credit: Jack Kelly Clark, UC IPM
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