If your croton are growing outdoors, I assume you live in a pretty warm climate. The most likely culprit when it comes to white powder on the leaves is powdery mildew, and the good news is that it can easily be treated: https://www.almanac.com/pest/powdery-mildew
If your plants don’t respond to powdery mildew remedies, it may be time to call your local extension service for more thorough diagnosis.
If your croton are growing outdoors, I assume you live in a pretty warm climate. The most likely culprit when it comes to white powder on the leaves is powdery mildew, and the good news is that it can easily be treated: https://www.almanac.com/pest/powdery-mildew
If your plants don’t respond to powdery mildew remedies, it may be time to call your local extension service for more thorough diagnosis.
https://www.almanac.com/cooperative-extension-services