Every stone fruit shares brown rot, and it overwinters on the tree: strip the mummies and prune the cankers before bud break, and keep fallen fruit picked up.
Promising · suboptimal if ignored → advise
How it works
Monilinia fructicola overwinters in mummified fruit left on the tree or the ground and in twig cankers; at bloom its spores blow and splash to blossoms, and infected fruit sheds spores that spread to other fruit on the same tree and to neighbouring trees, wild Prunus included.
What to do about it
Before bud break, remove every shriveled fruit still on the tree and cut out cankered twigs. Pick up fallen fruit through the summer, thin so fruit do not touch, and prune for air. Remove wild or volunteer Prunus nearby.
The evidence
Evidence: confirmed against 3 sources in the research-based literature.
the 3 sources
Penn State Extension, 'Stone Fruit Disease - Brown Rot', extension.psu.edu/stone-fruit-disease-brown-rot (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Brown rot is caused by the fungus Monilinia fructicola. It affects peaches, apricots, nectarines, plums, and cherries'; 'The fungus overwinters in mummies and cankers formed the previous season. The mummies persist in the trees or on the ground over winter'; 'Upon wetting, the spores are forcibly ejected into the air to be blown by the wind to blossoms'; 'Removing all rotted fruit after harvest helps to reduce the amount of fungus overwintering in orchards. In addition, remove dead or cankered wood when pruning.'
UMN Extension, 'Brown rot of stone fruit', extension.umn.edu/plant-diseases/brown-rot-stone-fruit (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Brown rot fungi overwinter in shriveled fruit, infected twigs and branches'; 'Infected fruit produce many fluffy, tan-to-gray spores that can easily spread to other fruit on the same tree and other trees'; 'Before bud break in early spring, remove all shriveled fruit that is still on the trees'; 'Cut out all branches with cankers and remove all twigs that have died from brown rot in February or March.'
Wisconsin Horticulture Extension, 'Brown Rot', hort.extension.wisc.edu/articles/brown-rot (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Brown rot is a destructive fungal disease of trees and shrubs in the genus Prunus, which includes peaches, plum, cherries, apricots and nectarines'; 'These fungi may be introduced into a garden via airborne spores produced on nearby wild or volunteer Prunus trees and shrubs. Insects such as sap beetles, vinegar flies and honeybees can also transport spores.'
Plants this fires on
Change history
Every change to this rule is one commit. This is what the project's version history records — the date and the reason — not a summary of it.
- rules: another rule here - brown rot across the stone fruits (verified) (O133 step 8)
Cite this page
Milpa Gardens. "Every stone fruit shares brown rot, and it overwinters on the tree: strip the mummies and prune the cankers before bud break, and keep fallen fruit picked up." Evidence grade: Promising. https://milpa.garden/rules/stone-fruit-shares-brown-rot-overwinters-tree/
A garden-planning corpus: every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.