Crepe Myrtle Decline/Stress

Asked August 20, 2018, 1:39 AM EDT

Thanks for taking my question. A lot of Crepe Myrtles did not do very well this year in my area. Specifically, I have a client with 12 good sized Crepe Myrtles, and most of them have only 10-20% foliage right now. This seems to have happened this year - the trees did not look "dead" last year. The client wants me to remove all the wood that is appearing dead, and reduce them all to the same height. I don't want to take off too much if some of this is just self-protective leaf drop due to stress. So I'm wondering, have you come up with a strategy for these defoliating Crepe Myrtles this year? Should wait till the end of the growing season and see if they leaf out some more? Should I wait till early next summer after they seem to have leafed out as much as they will for the year and cut off the leafless parts? Or some other method of determining what stems/branches are still viable, although maybe leafless now? I guess I could scrape the bark and see if it's green underneath, but that would be really tedious for 12 trees with 8-12 stems each. Please advise. Thanks, Jim

Hanover County Virginia trees and shrubs

2 Responses

Jim,

I don't interact with Crepe Myrtles too much in southwest Virginia because they generally are not cold hardy here. That might allude to the problem you're having. My best guess without any further information would point to winter injury of your crepe myrtles last year. Most are recovering well across the state and a bit of pruning would help neaten them up aesthetically. Judicious pruning back to the interface of dead ad live tissue on stems would be the approach. Whenever possible, try to make these shortening cuts back to a natural node...a lateral bud or a lateral branch. This will help control unwanted sprouting and promote the development of the natural growth habit.

It bears mentioning that there is also a new pest of crepe myrtle that is becoming problematic. It is called crepe myrtle scale...a sucking insect that looks like scabs on the stems. You should inspect the plants and make sure that it doesn't have those. Your local Extension office could help you with a diagnosis if you are unsure.

Call me if you have further questions. 540-231-5148

Regards,

Thanks Mr. Wiseman,
After reading your response and looking at other injured Crepe Myrtles I plan to take your advise and scout for scale and if I find none then prune back to live wood, hopefully at a lateral branch union or bud. I took a couple of scrapings from bark of another stressed specimen on Thursday and the branches/stems that were lacking leaves, which appeared to be dead, were in fact just that. No green under the outer surface of the bark, just dry, greyish brown wood. I think I'm in for a lot of hand sawing.
Thank you.
Jim