Brown Cherries on Rainier Tree

Asked May 31, 2019, 9:58 AM EDT

I have a Rainier cherry tree that produced lots of healthy looking blossoms followed by many green fruit, but now the fruit is all turning brown. Why is this happening, and what can I do about it?

Wayne County Michigan

1 Response

Hello,

This brown rot, a common disease on cherries. It is too late to do anything for the fruit. Follow the cleanup recommendations, below, for next year’s crop; then begin a spray schedule early next spring.

This response from Maryland Extension describes management of brown rot-

“Your tree is infected with brown rot is a common, destructive fungal disease that makes growing stone fruit a challenge for Maryland homeowners. Sanitation and properly timed fungicide sprays help to combat the disease. The fungus overwinters in twig cankers and in mummified fruit that is left hanging on the tree or has dropped to the ground. So, pick off and dispose of infected fruit (and fruit stems) from the tree and rake up any that has fallen around the tree.

Web page about brown rot:

https://extension.umd.edu/hgic/topics/diseases-stone-fruit

Apply labeled fungicides when the blooms are between 5-10% open, at full bloom, and about 2 weeks prior to harvest. It is best to apply fungicides before a rain event is predicted instead of waiting until after. Additional cover sprays will be necessary if we are experiencing a cool, wet spring and summer. Rotating fungicides helps to reduce the fungus from becoming resistant to the preventative sprays.

VA Tech home fruit spray guide:

https://extension.umd.edu/hgic/topics/home-fruit-preventative-spray-schedule

Fungicides available to home gardeners can prevent but not cure infections. Organic fungicides like sulfur and copper can be somewhat effective but may damage new spring growth.”

Here is a link to MSU’s Backyard Fruit page- https://www.canr.msu.edu/backyard_fruit/

And a care guide for cherries and other fruits-

https://ag.purdue.edu/hla/hort/documents/id-465.pdf

I hope this is helpful and you can get a good crop next year.

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