There is no denying that our winter temperatures have hurt many of our plants. I’m asked the question: Will my crapemyrtles die from the below zero temperatures? Dr. Carl Whitcomb answered that question for me since he has 70,000 crapemyrtles on his farm, plus he has several patented crapemyrtles and he hybridizes them at his research center in Stillwater, Oklahoma. His studies conclude that days of below zero temperatures can kill the tops, but the roots are still alive. He suggests NOT getting out your loppers or saws and start removing the tops. WAIT to see if the top of the plant is still alive. Do not get in a hurry; leave all plants in place until spring growth begins from the crown.
By next month you should know if the top of your plant is dead. Then it’s a matter of cutting it back to the ground. The roots are still alive and you will get growth from the crown with 10 to 15 new shoots. As new growth develops, begin selective pruning out the “extras” and saving the best ones to get back to the best 3, 4 or 5 stems, whatever your personal choice is.
Even if you nick the bark of crapemyrtles and they are still green, it will remain so for some weeks. The green under the bark remains because the roots were not damaged and are still moving water up through the dead cells of the xylem, thus protecting the damaged cells from dehydrating. So nicking the bark and seeing green is not a useful diagnosis at this time. Just wait and see what your plant will do rather than cutting back the top part of the crapemyrtle. If it becomes necessary to do that, it will take 2 to 3 years before your plant will have the shape and structure that you want. Patience is important at this point.
Good luck with all your crapemyrtles. It’s been a bizarre weather year; let’s hope the damage is minimal.