Q: I am writing to see if you have information about peach tree blight. I have two peach trees in Green Valley and both have been affected by a blight that causes the peaches to shrink in size and become inedible. Is there a treatment for this disease? Both trees have produced fruit for many years and are now advanced in age; one tree is 37 years old and the other over 30 years. They both still produce green leaves and fruit.
A: Improper pruning, not enough thinning of fruit, or poor soil fertility, can cause too small fruit. The other factor in your situation is the age of the trees. Peach trees don’t live forever and the average lifespan is around 15 years. I love old trees but if your goal is fruit production, the best thing is to replace your old trees with a couple of younger ones. Peaches typically start producing fruit by age 3 or 4 so if you can’t wait for fresh peaches, select a tree of that age to replace your older trees.
Peter L. Warren is the urban horticulture agent for the Pima County Cooperative Extension and the University of Arizona. Questions may be emailed to tucsongardensage@gmail.com.
