This post comes from Jason Griffin, nursery crop specialist and director of the John C. Pair Facility in Wichita, Kan.
This summer’s intense weather is undoubtedly affecting our trees this fall. Many un-irrigated trees gave up their leaves a while ago. Under conditions of exceptional heat and drought, early leaf abscission is a common survival mechanism for many deciduous trees, so don’t be too alarmed. However, your irrigated trees did not escape the summer unscathed either. Water, or no water, the intense heat throughout the state (and region) this summer had its impact. The stress is causing early defoliation and in some cases altering the development of fall color.
Take a good look at your trees. Did they have good growth this year? Were there several inches of new growth at the shoot tips? Does the bark on the branches and trunk look healthy and have good color? Is early leaf drop the only suspicious sign? If yes, then don’t lose too much sleep over early defoliation. It may just be a sign of the summer stress. However, if there was little to no growth and you can see regions of dead tissue on the trunk and branches, then it may be time for a consultation with your client. In short, 2011 was an unusual year. Don’t be surprised if your trees respond in unusual ways. If they were healthy going into fall, they should be healthy coming out of winter.
Article from Kansas State University Turf Blog.