Dormant spray for cherry tree

Asked January 13, 2021, 6:38 PM EST

We have a pie cherry tree (8yrs)...what should I spray it with in January? Beyond? Lost a lot of fruit after set.
Thx

Walt in West Linn

Clackamas County Oregon

1 Response

Hello Walt,

The loss of fruit on your cherry tree after blooming may be due to poor pollination. Cherries bloom early in spring, when the weather here can be cool and wet and pollinators are not as active. Cherry production in our area is sometimes not reliable because of that. Unpollinated fruit doesn’t develop normally, and drops off the tree. Encouraging pollinators of all kinds will help with cherry production. Sweet cherries also need a second tree for pollination, but pie (sour) cherries are self-fertile and don’t need a second tree. This article has additional information, Poor Cherry Crop Due to Lack of Pollination https://aces.nmsu.edu/ces/yard/1998/060198.html.

Cherry trees are susceptible to insect damage and to fungal diseases. Preventative dormant sprays can help keep your cherry tree healthy and productive. Fixed copper and lime-sulfur can help control fungal diseases and dormant oils applied in winter control insects by coating and suffocating insects without leaving behind insecticides that can harm pollinator insects.

Do not mix these pesticides. Always follow directions for dilution and spraying conditions on the bottles.

Timing is important. The first preventative treatment is made in late November, around Thanksgiving. Use a fixed copper spray at this time. The second treatment, and the most important is a lime-sulfur spray is early January. Two weeks after the sulfur spray, apply dormant oil. In mid February apply a second copper spray. Use separate tanks for each, (copper, sulfur and oil) spray. This article has additional information, Get a Leg Up on Fruit Tree Problems with Dormant Oils https://today.oregonstate.edu/news/get-leg-fruit-tree-problems-dormant-oils. All these products are readily available in garden centers.