How to Dig Up a Dahlia

Wait until the dahlia's foliage is killed or damaged by a frost in the fall. Before this, your dahlias are busy photosynthesizing sunlight into energy and storing that energy in their tubers for next year. Cut the tops off, but leave 2 to 3 inches so you know where your dahlias are located.

Dig around your clumps of dahlias, about 2 to 3 inches away from the plants. Dig down approximately 6 to 8 inches to clear as much of the tubers as possible. Use a garden fork, which will not damage the roots as much as a shovel or spade would.

Carefully remove the plants from the soil by pushing down on the garden fork's handle. Do this all around the plant to loosen the soil until you can easily lift the plant out of the ground. Brush the excess soil off.

Wash off the remaining soil with a garden hose. Washing off the soil is only recommended for some tender bulb-like structures, and dahlias are one of them, according to the University of Minnesota.

Dry the dahlia tubers in an airy location for several days, but out of direct sunlight. Brush them with powdered sulfur once they are dry and store them in paper bags in a dark, cool area of your home, such as the garage. Do not let the dahlia tubers freeze. Replant in the spring after the last frost.