Library Article

Brown Rot

A fungal fruit rot common on stone fruit that causes brown, fuzzy decay on fruit in the orchard or on the kitchen counter.

  • Disease
  • Jun 15, 2026
  • Peach, Cherry, Plum

Reviewed by Daniel Dick · 2026-06-15

Why it happens

Brown rot is caused by Monilinia fungi. It affects peaches, nectarines, cherries, plums, and apricots. The fungus can start at bloom but is often most visible as fruit ripen. Warm, humid weather near harvest increases risk.

What to check next

  • Is the rot fuzzy on the surface, or more of a soft wet decay?
  • Are mummified fruit still on the tree or on the ground?
  • Did fruit touch each other on the branch or in a bowl after harvest?
  • Was there hail, insect, or bird injury that opened the skin?

When to get more help

Consider local advice if rot destroys most of the crop several years in a row, if trees fail to carry fruit to harvest, or if you need help matching timing to labeled products.