When November comes and the first hard frost hits, your dahlias stop blooming. The blackened leaves mean their summer display is over, but it’s also time for an important winter job: lifting and storing the tubers. If you garden in a cooler climate, leaving dahlias in the ground can be risky because cold and wet soil can kill the roots.

It’s important to lift dahlias at the right time. Wait until the leaves turn black after the first hard frost. This tells the plant to send its energy into the tubers for next year. Once the tops are black, cut the stems to about six inches. Use a garden fork and start about a foot away from the main stem to gently loosen the soil. Carefully lift the whole clump out, making sure not to break the area where the tuber meets the stem.

Once you’ve lifted the tubers, get them ready for storage. Gently brush off most of the soil, but don’t wash them because that can cause rot. Many gardeners let the tubers dry in a cool, dark, and airy place for a few days so the skin can harden. After this, they’re ready to be stored for winter.

To store tubers, keep them cool, dark, and just dry enough to stop mold but not so dry that they shrivel. Use wood shavings or vermiculite as a storage medium. Put the tubers in cardboard boxes or paper bags so they don’t touch, and cover them completely. Store the boxes in a frost-free place like a garage, shed, or cellar, where the temperature stays between 5 and 10 degrees Celsius. Taking these steps in November helps ensure your dahlias will bloom beautifully again next year.