Wet springs cause peach leaf curl

Q. Why are the leaves on my peach tree curly? They have bumps on the leaves.

Ethel from Salem

A. This year’s spring weather has been the perfect storm for peach leaf curl. It’s a disease we only hear about in years with cool, wet springs. This year’s weather had a long period of perfect weather conditions to make this disease rather severe in backyard orchards.

The disease is first noticed on leaves. The leaves twist, with portions of each leaf turning reddish and bumpy – resembling large blisters on individual leaves. The leaves eventually darken and fall from the tree. In severe cases, fruit is affected and falls from the tree as well.

The disease is “once and done,” meaning it does not spread to any new leaves that emerge after the initial infection. Peach leaf curl can reappear next spring if conditions are favorable. It is thought that the disease has more time to infect the immature tissue based on the plant’s slow growth during periods of cool spring weather.

The fungus survives our winters on the bark surface and the dormant buds. Thus, one fungicide application will do the trick. The spray application must be applied during the dormant period before the first buds begin to swell in spring. For organic production, lime sulfur is a popular choice for control. There are other options as well. Be sure to read and follow all label directions when applying any chemical – organic or other.

To learn more about this disease, symptoms and control, visit go.osu.edu/peachleafcurl.

Eric Barrett is OSU Extension educator for agriculture and natural resources in Mahoning County. Call the office hotline at 330-533-5538 to submit your questions. Regular clinic hours are 9 a.m. to noon Mondays and Thursdays.