The peak of fall is behind us in Delaware County. We were lucky to get a brief, beautiful showing Columbus day weekend, but now the hills taking on the muted tones of winter. What happened?
We began seeing leaf drop before the fair, and signs of distress even earlier in the summer. The cool, wet summer caused a proliferation of fungal diseases, which impacted numerous tree species. The hardest hit by far in our county…apples. I fielded apple calls just about every day in August and September. It started as spots on leaves and fruit, and escalated into totally bare trees. Some were loaded with fruit, some had no fruit, but a major theme was leaf drop. The major culprit – apple scab disease. This common disease affects most apples and crabapples that aren’t treated on a yearly basis, but it usually isn’t problematic. A spot here or there doesn’t really take away from the beauty of the tree, and the apples are still tasty for humans and wildlife.
This year, the trees decided to cut their losses, and dropped their leaves. Some varieties pumped their surplus resources into fruit production, which resulted in early ripening. Other varieties dropped their apples before they even had a chance to ripen.
Maples, our leaf-color superheros, were also affected by the damp conditions. Tar spot, another common fungal pathogen, hit the maples hard and early this year. Like the apples, the leaves just fell off the tree without any noteworthy color change. Luckily, not all varieties are sensitive, and we did see some gorgeous oranges, yellows, and reds.
Now here is the GOOD NEWS…the trees should be just fine as long as we don’t have multiple back-to-back years like this one. The absolute best thing you can do this year is to rake up and dispose of your leaves. I’m usually adamant about mulching and composting leaves, but the sick leaves need to go. If you live in a village, put them out for curbside pickup. In the country, either relocate the leaves to an un-used part of the property to decay naturally, or speed up the process in place by mowing over the leaves. You can also add a dilute solution of urea as described in this article.
For next year, consider treating important ornamentals and small fruit trees with a fungicide in the early winter/late spring (see this publication for more information).