Do I have to dig up my dahlias in the fall?

Yes, it's generally recommended to dig up dahlias in the fall before the first hard frost. This helps protect the tubers from freezing temperatures, which can damage or kill them. After digging them up, clean the tubers, let them dry, and store them in a cool, dark place for winter. If you live in a mild climate, you might be able to leave them in the ground, but ensuring proper winter protection is still important.