Then, around Dec. 15 the second spray is needed, both on the east and westside of the Cascades. The third treatment should follow in the late winter, around Feb. 15. Most peach owners will spray a fourth time as leaf buds begin to swell and start showing a little green. Symptoms of peach leaf curl appear in the spring, and include curled, distorted and reddened leaves. As the disease proliferates, thickened areas on the leaves turn yellowish-gray and velvety.
Spores are then ready to spread to healthy leaves.
During wet, rainy seasons, the infection is spread over the tree to leaf buds and can become so heavy that the tree is defoliated and will drop fruit that may have been starting to form. Use a good positive action or pressure sprayer, Penhallegon advised. Lime sulfur or Bordeaux with at least 50 percent copper are most effective. Always follow label directions. If in the spring, when leaves come out, a few infected leaves appear, it is too late - your peach or nectarine tree is infected, Penhallegon warned.