crape myrtle distress

Asked May 30, 2018, 4:09 PM EDT

Hi, I left a telephone message about powdery material on my crape myrtle and then took some photos that I thought might be helpful. In addition to the surface material, some of the trunks have gotten quite dark. Maybe there are several problems taking place. Look forward to getting some help on this. Thank you.

New Castle County Delaware disease plant disease crape myrtles trees tree

4 Responses

Your crepe myrtle appears to be suffering from bark scale a fairly recently pest introduced from the Far East. Here is a good article describing the pest and treatment. https://www.gardeningknowhow.com/ornamental/trees/crepe-myrtle/crepe-myrtle-bark-scale.htm Your crepe myrtle appears to have lots of preexisting decay that is also stressing the tree. Though you may, through treatment, manage the effects of white scale, the tree may already be seriously compromised.

Thank you for the articles and comments. I plan to do a power wash to get rid of the scale and follow that with Neem Oil treatment.

You were understandably pessimistic about the turnaround on these crepe myrtles. You are probably right. I did power wash and treat with Neem Oil. I will do my third Neem treatment tomorrow but the results are not dramatic if any. Two trees are clearly affected. Both have some new shoots on limbs that appear to be active. Both have limbs that so far have no new growth. Do I cut the "dead" limbs to prevent further deterioration? If so, when is the right time.? Any other steps to take now??

Crepe Myrtles have also suffered from the late, severe winter weather this past year. Lack of growth in the canopy may well be attributed its effects. This is a widespread problem in our area this year. It is possible that barren areas you are seeing in the canopy can recover, but not this year. I think at this point a better option is to prune out clearly dead branches now. Check other branches for flexibility. This will give you some indication that they are still alive and may recover over time. However, if you do not want to look at patchy Crepe Myrtles for a year or so, cut out the unproductive branches while trying to maintain the overall natural shape. You can do this now, or wait until the fall.