A reader, Gwen, wrote to ask me why apples are dropping so much fruit this year. A “June drop” is normal and can continue for about eight weeks. Yet, trees are still dropping fruit. A tree that is stressed will often drop fruit to conserve energy. Stress factors can include too little or too much water, lack of nitrogen, too much nitrogen, and/or long dry hot spells.
We lost most of the apples on our trees. Maybe I overwatered? Although I didn’t fertilize this year, the density of leaf growth leads me to suspect nitrogen is not the issue. I attribute this long-lasting fruit drop to the heat and wind. I can’t remember the high temperatures starting so early in June and continuing for so many weeks.
Diseases and insects also contribute to fruit falling off trees. Our fifty-year-old apple tree has a bacterial disease called fireblight. However, the tree grows vigorously so I doubt that fireblight is causing fruit to drop. Codling moths have infested the apples with their wormy larvae and these fruits traditionally fall early.
Ground squirrels, which don’t seem to pay attention to the “ground” part of their name, climb the trees and knock the fruit down. Since the wind has been so helpful blowing the fruit off the trees, the squirrels haven’t had to do too much climbing this year.
I never thought I would find a benefit to ground squirrels, but they do eat up the fruit on the ground or carry it away to their dens, leaving less windfall for me to have to remove. Birds also become pests as they peck away at the apples in the trees often causing the fruit to drop in the process.
I’m not sure there are any completely effective methods of preventing fruit drop beyond good cultural care. We are at the effect of a lot of factors. Be aware that it is necessary to pick up the downed fruit and get rid of it. If you leave the apples on the ground, all the worms in the fruit become codling moths that ruin next year’s crop.
Additionally, all that sweet rotting fruit attracts yellowjackets. Although fallen fruit may carry diseases picked up from the ground, I sort through the apples, taking any decent ones and scrub them in soapy water. Then, I use them for baking or making applesauce.
Ah, the trials and tribulations of being a gardener!
JoAnne Skelly is associate professor & extension educator emerita at University of Nevada Cooperative Extension at skellyj@unr.edu.
