Peach leaf curl is a common fungal disease affecting peaches and nectarines. It can affect leaves, shoots, blossoms, and occasionally fruit.
Symptoms typically appear in spring, when emerging leaves become distorted, thickened, curled, or puckered, often developing reddish or purple discoloration. Infected leaves may eventually turn yellow or brown and fall off. Severely affected trees may produce a second flush of leaves, which uses energy reserves and can weaken the tree over time.
Unfortunately, once symptoms appear in spring, it is too late to treat the infection that season. Fungicides are effective only when applied preventively, while the tree is dormant and before buds begin to swell or open.
To prevent peach leaf curl, apply a fungicide labeled for peach leaf curl during dormancy, typically in late fall after leaf drop or early winter. In areas with high rainfall or a history of severe infection, a second application late in the dormant season may be beneficial, following the product label and UC IPM recommendations. Treatment generally needs to be repeated every year.
The good news is peach leaf curl rarely affects the fruit, so you should still be able to enjoy your fruit harvest though it may be diminished. However, severe or repeated infections can reduce yields and weaken the tree. Maintaining good tree health through appropriate watering and care can help the tree recover.
For more information, including recommended treatments, see:
UC IPM Pest Note 7426: Peach Leaf Curl