This is a typical consequence of this style of pruning, and for the time being, little can be done to remedy the situation. It appears that the plants were topped, a pruning practice that is not recommended for trees and which can lead to long-term problems with their health and appearance. While vigorous growers like Crapemrytle rebound well from such pruning, the branch attachments of the regrowth is not optimal and more likely to be weak and prone to breakage, especially as the new growth extends in length due to lush growth and puts strain on the connection point with the older branch. Those younger shoots also sometimes do not bloom as well as older branches would, and rain weighing-down those flower clusters further increase the risk of breakage due to that inherently weak connection point between the new growth and the old wood.

The proliferation of suckers (growth out of the roots or base of the plant), which by itself can be normal on Crapemyrtle, in this case demonstrates that the plant is under stress from the pruning. (It may also be under drought stress, as even drought-tolerant plants are currently being taxed too much by this ongoing drought.)

Monitor the plants for watering needs as you are able, to help alleviate at least some of the stress on these and any other trees and shrubs in the landscape. Sometimes secondary issues like a canker infection can set in following stress by drought, even if a plant isn't showing obvious signs (wilting, etc.) at the time; such diseases cannot be cured, so prevention is important.

Crapemyrtles should not need pruning except for minor corrections to branch structure (if two are crossing over each other, for example) or small tweaks to mature shape. Drastic changes in height can be avoided by growing a cultivar better-suited to areas with limited space, rather than pruning a large-maturing variety to fit a smaller space. Pruning also does not improve flowering; rather, it can hamper good blooming. We recommend that either pruning be limited on these plants going forward, or that they be replaced with smaller-growing cultivars if their full size would be too big for where they are growing. The information in the pages below might be of interest:

• Pruning Crapemyrtles -- Virginia Tech
• How Do I Prune Crapemyrtle? -- NC State
• Tree-Topping: The Cost is Greater Than You Think -- Penn State (not crapemyrtle-specific, but still applicable)

For now, any branches that have snapped can be pruned off, as they will not recover. Feel the soil around six inches deep in the root zone and water well if it has become somewhat dry to the touch at that depth. (If damp when checked, watering is probably not needed yet.)

Miri

Ugh. Thank you Miri.  I guess I should have asked about trimming before hand.  I had seen other Crapemyrtles pruned this way, but now that I think of it they were smaller trees-much smaller. 

You're welcome.
Indeed, crapemyrtles are often pruned that way by poorly-trained landscapers or gardeners who aren't aware of the damage it does to the plant. The age or size of plant that is pruned this way is not a factor that matters much with regards to the damage done to tree structure and wood sturdiness as the plant matures and regrows after each pruning. Perhaps the practice continues among landscapers because the plants seem to regrow fairly well, despite the negative impacts on the trees.

Miri