Host Mayita Dinos demonstrates the proper way to winterize dahlias. To survive the winter, these flowers must be excavated and preserved in the fall. The best time to dig dahlias out of the ground is about two weeks after the first hard frost, when the plants have turned brown. Mayita explains that during the frost, the tubers are "cured" under the ground, which prevents them from shriveling too much in storage; those that are not cured prior to storage will be "green" and shrivel badly or even rot. (If a hard frost has not occurred by mid-November, the number of cold nights has most likely slowed plant growth enough for curing to occur, and it should be safe to go ahead and dig up dahlias for storage.) Mayita offers these step-by-step instructions:
- Cut the stalk off to about 6".
- Gently lift the tubers from the soil with a spade or pitchfork.
- Wash the dirt from the roots with a garden hose.
- Allow the roots to dry in a protected area.
- Pack tubers with an equal volume of peat moss in a plastic bag that has small, pre-punched holes. (Crates or cardboard boxes lined with about nine or 10 newspaper pages can also be used for packing.) Use sand, dry sawdust or additional peat moss as a storage medium.
- Store dahlias in a cool, dry area with a constant temperature of 40-45 degrees.
