Have Your Trees Started Dropping Their Leaves Already?

— Written By Bill Hanlin and last updated by JoAnne Gryder

Mary's early Fall Color 010I have noticed that quite a few trees appear to be dropping their leaves early this year. We have a maple tree in our yard that has dropped almost half its leaves while another maple next to it looks fine. If you have trees that are shedding their leaves early, you may be wondering what is causing the problem and will it harm the tree?

Trees drop their leaves early for a variety of reasons. Leaves that have been infested with insects or diseases will, often, drop early. The maple in my yard has disease tar spot, which is causing the leaves to drop now. Pests like scales, mites and white flies can also cause early defoliation. Spraying a pesticide will eliminate the infestation, but may not be practical for large trees.

Some trees are just not suited to our hot summers. Trees like ornamental cherries will, typically, drop their leaves during the summer due to heat. If you go to the mountains, these same trees will still have their leaves because of the cooler climate.

Another reason trees drop their leaves early is drought stress. We have had a couple of dry periods this summer which can put considerable stress on area trees. Mulching and deep watering will prevent the tree from being stressed in dry years.

You can prevent defoliation problems by putting the right tree in the right place. Avoid planting trees that are prone to insect and disease infestations. Also avoid planting trees that are not adapted to our climate and hardiness zone.

Will early leaf drop damage the tree? If the premature defoliation is a rare occurrence, the tree should survive with no problems. However, early leaf drop that occurs year after year may ultimately weaken the tree and reduce tree survival.