A: The question answered itself once we asked how often the bed was being watered. A good, solid soaking once every other day makes the crape myrtle happy, and the sedum tolerated it within reason… but the other plants need dry conditions, or at least a lot drier than they were.
The droughts of the past two decades have made xeriscaping, the practice of using plants that need minimal or no additional irrigation, popular. There are a number of excellent plants that do well in dry conditions, dry enough that at times one must take care that a rainy spring won’t cause a problem! But these plants should be used in beds that contain plants with similar water requirements. This bed was watered much too much for these plants to survive.
That being said, crapemyrtle is more drought tolerant that most would think, once well established. If this plant had been individually hose watered the first year and second summer, it likely would have been possible to hit a happy medium that would have made the whole bed work.
Burton specializes in diagnosing and solving plant problems. If you have a question for Burton, please email him at email@example.com and include photos showing the problem.