Crape myrtles losing leaves

Asked September 7, 2013, 4:28 PM EDT

My crape myrtles are losing leaves and look awful. 7 crape myrtles, full sun, 8 ft tall, 4-5 years old. There are hardly any leaves. Those that remain have brown spots, then turn all brown and drop off. I can't see any bugs or any white stuff or any black stuff on them. I thought it was Cercospora, from my research but the person at the garden center said that while it looked like fungus was there, she did not feel it was enough to cause the defoliation. They look awful and I'm afraid they will die. Can you help?

Howard County Maryland

5 Responses

Cercospora has caused havoc this year with crape myrtles all over the state. Other forms of cercospora have turned up on other species where it does not normally present a big problem. It probably all goes back to the unusual amount of rainfall, cool temperatures and overcast days that we had earlier this spring and summer.

It is typical for the symptoms of this disease to be delayed until late summer and fall, though the infection occurred earlier. Normally, an infected shrub looks good for most of the season and it's too late to spray a fungicide by the time symptoms occur. If it is convenient, you can rake up the fallen infected leaves and dispose of them. With a return to normal weather, the crape myrtle should return to normal.

ECN

Thank you for the insights. This is the second year in a row that this has happened. No other crepe myrtles in my neighborhood look like this. . . but that may be coincidence. Are you sure there's nothing else to do? Should I schedule something for the spring so I catch it early? I'd hate to have them die.

Make sure your crape myrtle gets plenty of sun by pruning back other plants that constantly grow and may be making it shadier and shadier. Also prune it to improve it's air circulation to promote fast drying after rains if its foliage has gotten dense.

Be sure to rake and pick up all the diseased leaves, so that you reduce the amount of diseased material that will reinfect the plant next year. This way you break the cycle in your yard.

You can spray a fungicide preemptively next year. (Fungicides protect from disease, but do not cure disease once a leaf is infected.) Watch the foliage closely and when you see one infected leaf, pull it off and spray the rest. Do not spray when a plant is in bloom. Spray before blooming begins to protect pollinators.
ECN


Thank you very much.