Frequently Asked Questions

  Apple trees are, surprisingly, quite drought tolerant. However, there are many varieties that are susceptible to powdery mildew, which can cause the type of leaf curl you're talking about.    Although, the trees themselves can survive well in a drought, they won't produce much of a crop that way. So, most apple tree growers keep the trees well watered. You can practice good "orchard floor" management (even if there's only a few trees in your yard) to reduce the lawn's competition for available soil moisture and allow the trees to get that water. Ideally, there should be no grass (or other plants) growing within the dripline of the tree. The dripline, in case you've never heard of it, is an imaginary line at the outer border of where water might drip from the tree leaves.  About one-third of the tree's roots will be within that area.   Keeping that area plant-free and mulched will help keep the tree healthy and vigorous.  

Here are links to more information about powdery mildew on apples:
   http://www.ipm.ucdavis.edu/PMG/selectnewpest.apples.html

http://utahpests.usu.edu/plantdiseases/htm/fruit/applepowder/applepowder
images
   http://utahpests.usu.edu/plantdiseases/htm/fruit/applepowder

   Here are links to more information about other possible pest
problems of
apples:
   http://www.ipm.ucdavis.edu/PMG/r4100311.html