How to Winterize Your Dahlia’s

How to Winterize Your Dahlia’s

Dahlias are not hardy in cold climates, and their tubers can’t survive freezing temperatures in the ground. Once frost hits, the lush blooms die back, but the roots beneath still hold next year’s potential. To keep that promise alive, dahlias need to be lifted and stored indoors through winter. Proper winterizing protects the tubers from rot and freeze damage, ensuring you can replant them in spring for another season of vibrant, show-stopping flowers.

Winterizing Process

  • Lift roots: cut stalks to 4″ above ground level after the tops turn yellow and are frosted

  • Dry clump: Dig a 2 ft. clump with a spading fork, shake off the loose soil, and let the clump dry in the sun for several hours

From that point, follow either of the following root storage methods:

Division Method:

  • Divide clumps immediately after digging — freshly dug roots are easier to cut, and the eyes (growth buds) are easier to see.
  • Cut the stalks with a sharp knife, leaving about 1 inch of stalk attached to each section.
  • Ensure each division has at least one eye (growth bud) so it can produce a new plant.
  • Dust all cut surfaces with sulfur to help prevent rot.
  • Bury the divisions in sand, sawdust, peat moss, or perlite for protection during storage.
  • Store over winter in a cool (40–45°F), dark, and dry place until ready for replanting.

Intact Method:

  • Leave clumps intact — do not divide them in the fall.
  • Cover clumps with dry sand, sawdust, peat moss, or perlite.
  • Store in a cool, dark, and dry place (as described in the division method).
  • This method helps prevent roots from shriveling during storage.
  • 2–4 weeks before spring planting, separate the clumps:
  • Cut them apart as described in the Division Method.
  • Place all roots—whether divided in fall or spring—in moist sand to help them plump up and encourage sprouting before planting.

By giving your dahlias the right winter treatment—cutting the tops back, lifting and cleaning roots, and storing them in a cool, dry, dark location (whether divided or left intact)—you greatly increase their chances of emerging strong and healthy in spring. These careful steps protect them from freezing, rot, and over drying. When the growing season returns, simply replant or divide the clumps as needed, and your dahlias will reward you with vigorous blooms year after year.