Dahlias are perennial in zones 8-10, but in cooler zones, tubers can be dug after frost comes, stored over winter, then re-planted the following spring. Grow Dahlias in a sunny spot, in average soil that drains well. Keep moisture consistent once it begins to grow and enjoy a non-stop color parade. Deadhead spent blooms to encourage more flowers and pinch off small side buds to encourage larger flowers if desired.