Peach Leaf Curl
Taphrina deformans
A common fungal disease of peaches and nectarines that puckers and reddens the spring leaves into thick, curled, distorted masses. One of the most recognizable backyard fruit-tree diseases, it weakens the tree and cuts the crop, but it is also one of the easiest to prevent with a single well-timed dormant spray.
🔎 How to spot it
Look in spring for new leaves that are thickened, puckered, and curled, flushed red to purple, then turning yellowish and finally grayish-white as a velvety bloom of spores covers them. Distorted leaves later brown and drop. Severely affected shoots are stunted and swollen, and the disease can also distort blossoms and young fruit.
🥀 Damage it causes
The curled, distorted leaves cannot feed the tree well and soon drop, and the tree must spend stored energy growing a second set, which weakens it. Repeated yearly infection reduces fruit set and size, stunts shoots, and over time can seriously decline a tree; a heavy case can cost much of the crop.
🔬 What causes it
Peach leaf curl is caused by the fungus Taphrina deformans, which overwinters on the bark, twigs, and bud scales of the tree. In spring its spores infect the new leaves as the buds swell and open, and cool, wet weather, roughly 50 to 70 F, during that emergence strongly favors infection. Once leaves are open and dry, new infection largely stops.
🛡️ Prevent it
The disease is controlled by a dormant spray, not by treating the curled leaves later. Apply a fungicide such as a copper product or lime sulfur once in late fall after leaf drop, and again in late winter before buds swell if the winter is wet, to coat the bark and buds before the spring infection period. Plant resistant varieties where available.
🧯 If it is already here
Once leaves are curled in spring there is no spray that will cure them, so the response that season is to keep the tree healthy: water and feed it to help it push a second flush of leaves, and rake up and remove fallen infected leaves. Mark your calendar to apply the dormant spray the following late fall and winter, which prevents the next outbreak.
💡 Good to know
Peach leaf curl is unusual in that timing is everything: the only effective treatment is the dormant spray applied months before symptoms, while spraying the curled leaves does nothing. A single properly timed application generally gives good control, which is why this alarming-looking disease is also one of the most preventable.
🌱 Plants it affects
5 plants in the library can be affected by this problem
For educational and informational purposes only. Disease management advice is general guidance drawn from university cooperative extension sources; always identify a problem positively and read and follow the label on any product before use, especially around food crops, children, and pets.