Why Is My Crepe Myrtle Dropping Leaves?

October 11, 2012 | By | Comments (3)
'Miami' crepe myrtle

‘Miami’ crepe myrtle. Photo by Steve Bender.

Question from Desperate Reader: I have two red crepe myrtle trees. Both started dropping leaves in midsummer and are now almost bare. I sprayed them with fungicide during the humid months, but they never did rebound. Any suggestions?

Grumpy’s Totally Correct Answer: I feel certain your crepe myrtles are infested with a fungus called Cercospora leaf spot. Mine has the same problem and it seems especially prevalent this year. Unfortunately, while breeders have produced many selections resistant to powdery mildew, a common malady of older crepe myrtles, they haven’t given us many that resist this leaf spot. And with more crepe myrtles being planted every day, the problem will probably get worse.

The good news is that this leaf spot doesn’t seem to really hurt an infected crepe myrtle, even if the tree drops all of its leaves prematurely. It still blooms the same. What can you do to keep leaf spot from showing up next year? First, rake up all fallen crepe myrtle leaves and throw them out with the trash. Next summer, spray according to label directions with a fungicide called Immunox. You can get this at garden centers.

Grumpy’s on Vacay!

Santorini

The isle of Santorini. Photo by HBarrison.

That’s right! For the next couple of weeks, Grumpy will be cruising to exotic locales all over the known world as he seeks to recharge his gardening batteries. He will not be able to check email during this time, so either wait until October 29 to post a gardening question or wait patiently for an answer.

Don’t think Grumpy has abandoned you. In the time I’m away, I will be answering a gardening question sent in by a faithful reader right here every Tuesday, Thursday, and Sunday.

Now could I please have another glass of red?

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Next Post: Black Spot on Roses

COMMENTS

  1. Karen

    I was wondering if you have any thoughts or information on using cornmeal to promote beneficial fungus in soil which competes against pathogenetic fungi?

    October 11, 2012 at 11:36 am
  2. Karen

    p.s enjoy your vacation. If you are going to Santorini I am so jealous. I was there 30 years ago and it was fantastic.

    October 11, 2012 at 11:37 am
  3. Steve Bender

    Karen,
    I haven’t heard about this. All I know is that some people use corn gluten as a weed preventer. Mixed results for me.

    October 29, 2012 at 4:32 am