Q: My dwarf crepe myrtle bloomed in July---a beautiful deep red/watermelon color---same color it has been for ten years. I deadheaded the blooms, fertilized it, and two weeks ago it bloomed again. Guess what? It was pink. What happened to my beautiful red blossoms? Now the blooms are either pink or coral on same stems. I had repotted it in February and fertilized it.
A: The Grump thinks the color change is related to the weather. Temperature and strength of sunlight can affect flower color. For example, flowers of some of the newer bright red crepe myrtles, such as 'Dyamite,' open white on a cloudy day. This is because the pigment responsible for red coloration, anthocyanin, is produced only in the presence of sunlight. I'll bet your plant will be back to its original color next summer.