Dahlias and other tender plants that grow from tubers and bulbs often require digging and storing in a frost-free place over the winter months to provide protection from cold damage. Gardeners remove dahlia tubers in fall before temperatures drop too low and store them in a warmer environment until the soil is workable in spring. Without proper storage, dahlias will not bloom the following year, which makes this part of the process essential to the plant's survival. Before storing, dahlias must be cured and dried to prevent rotting, but the process takes little effort to complete.
Dig up dahlia tubers after frost has damaged the foliage of the plant. Carefully loosen and remove the soil from around the plant until the tuber is exposed, and then gently lift it out of the soil. Sever the foliage from the tuber, allowing only 3 inches of stem to remain.
Use a water hose to rinse excess soil and debris from the outside of the tuber. Set the dahlia tuber in a frost-free location that is protected from both the sun and wind, and allow it to dry for one to two days.
Insert the tuber into a plastic bag, and then punch four to six holes in the bag to allow adequate air circulation. Fill the bag the rest of the way with peat moss to absorb excess moisture and reduce the risk of rotting or disease.
Store the filled bag in a dry, dark location with a consistent temperature of about 40 to 50 degrees Fahrenheit. Do not exceed 50 degrees Fahrenheit, or the tuber will sweat and this increases the likelihood of it developing fungal diseases.
Check once every two to three weeks to ensure the tubers have not shriveled or become diseased. Snip off any diseased portions, or submerge the tuber in water if shriveling has occurred. Allow the tuber to dry completely before returning to storage.