Wondering what’s wrong with your plant? We love talking plants and are always happy to help with any gardening related questions!
Question: “My peach trees have distorted leaves and I do not know what is wrong. What is happening to my trees and what should I do to stop it?”
Answer: This is caused by a fungal disease called Peach Leaf Curl. This is a disease that is not uncommon in peaches when there is cool, wet weather in the spring, as we have had this season. Infected leaves have odd, distorted, lump, gall-like growths, often with a red-brown color and they may be twisted. Usually the infected leaves will drop after a few weeks. At this point, these leaves can be raked up and disposed of.
Applying fungicides in spring after leaf curl symptoms appear is not helpful in controlling peach leaf curl disease, as the fungus grows inside the leaves and is protected from contact with fungicides. The best time to apply fungicides to treat this disease is in the fall, after all the leaves have dropped from the tree. Using a copper spray or a product containing chlorothalonil (like Bonide Fung-Onil) at this time will kill overwintering of spores that could infect the tree the next spring. You can also make a second fungicide application in early spring, before the tree leafs out for additional protection.
Although early leaf drop from peach leaf curl disease can be somewhat stressful to peach trees, it is usually not significantly harmful. You can feed the trees with a balanced fertilizer (like 10-10-10) at the recommended rate after the infected leaves drop if you have not fertilized the trees this season to promote vigorous regrowth.
Here is a link to a University of Wisconsin extension publication about the disease: https://hort.uwex.edu/articles/peach-leaf-curl/
Allen R. Pyle is the lead horticulturalist at Jung Seed Co. and has been a professional horticulturist for over 20 years, with decades of experience in gardening and landscaping. Allen has degrees in both horticulture and entomology from Michigan State University. He has extensive experience in plant propagation, pest management, growing perennials, and organic gardening. His knowledge spans a wide range of plants, including edibles, ornamentals, herbs, weeds, and native species. Allen is passionate about plants and gardening and is always happy to share his knowledge and expertise with others. He regularly speaks and writes on plant-related topics for both professional and amateur gardening audiences. Allen is also certified in Permaculture design.