How to treat peach leaf curl

Peach leaf curl is caused by a fungus that affects only peaches and nectarines. You may see distorted, reddened foliage, and thickened or puckered leaves and shoots in the spring.

Trees should be treated with a fungicide in the late fall and winter each year. If you didn’t treat your tree last fall (or even if you did), you can still use an application now before buds swell.

The safest fungicide for home gardens is copper octanoate or copper ammonium, a fixed copper fungicide. Mixing the fungicide with 1% horticultural oil will increase its effectiveness. It is important to wear protective clothing when applying the material. Spray the branches and twigs completely to ensure that all spores are killed.

You will be rewarded with delicious fresh peaches come summer.

— katie martin, uc marin master gardener