sycamore trees dropping dead leaves all summer

Asked August 19, 2016, 12:35 PM EDT

Our sycamore trees have been dropping dead leaves all summer and our yard looks like it's fall. We live in Baltimore City and the trees are well over 50 years old. Are the trees dying?

Baltimore Maryland

7 Responses

Anthracnose is a disease brought on by wet, cool conditions in early spring, Sycamore is very susceptible to this disease,fortunately, it produces new leaves throughout the spring and will recover. The older ,diseased leaves are what you see on the ground.See the attached publication for preventative ,control measures.


I hope this is the problem our sycamore trees have, but the leaves do not look diseased as they do in the picture. The leaves in our yard are brown and dead, like they are in the fall.

This sounds like a stress sign. It is not unusual for sycamore leaves to drop their leaves this time of year. There are enough nutrients in the root system to put out new growth next year. There is nothing that you need to do. If you have a lot of leaves smothering the grass, shred and put in your compost bin, wooded area, or yard recycle.

We have never in 50 years fertilized the tree. Should we do it now? And if so, what should we give? Thanks!

We just received the below email from a respected tree company we have used in the past. The company suggests adding the potassium phosphite to stressed trees. Do you agree with this?
Thanks very much.
"It's important to note any changes in your trees in August. Trees under stress from hot, dry weather often display key symptoms that indicate a problem exists. Some things to look for:

  • wilting or unusual loss of leaves or needles;
  • yellowing of leaves or browning of needles;
  • premature autumn color and leaf drop;
  • wet, sappy spots on branches and stems.

To aid stressed trees, I am now recommending the application of potassium phosphite. This new treatment improves a tree's ability to resist disease and tolerate environmental stress.

Given the challenging growing conditions typical of late summer, it is important to have your trees and shrubs checked before serious issues develop...."

In general healthy, mature trees do not usually benefit from fertilization. Trees in the landscape receive nutrients from turf fertilization, grass clippings, fallen leaves and natural soil fertility.
Before fertilizing Test your soil for pH and nutrient deficiencies. Results will let you know if there are nutrient deficiencies.