Keeping Dahlias For Next Year

As we inch toward our first hard frost, it’s time to decide if you want to keep your Dahlia tubers for next season or not. If you want to keep Dahlias for next season, here are the steps for doing so. In general, we wait to dig these plants until after the first frost but before the ground itself freezes.

1. If you see that hard frost is predicted, you might want to cut a big bouquet of the flowers. At the same time, if you’d like to remember what color flowers a tuber produces, either write it on a plastic stake and place it at the base of the plant, or write it on a piece of plastic flagging tape and tie it around the base of the largest stem.
2. After the frost, cut the stems and old foliage off leaving about 6 inches of stubs. Use a garden fork or a shovel to dig the tubers, sticking that tool into the ground about 8-10 inches away from the stem stubs so that you won’t cut into the tubers.
3. Shake the soil off the clump and set them aside while you dig the others.

4. Wash the soil off with a stream of water, then place the clumps on a tarp or newspaper under cover so they can dry out. If the temperatures are predicted to go below freezing, put them in a garage or enclosed porch so that the tubers don’t freeze while they dry. Most need about a week to air out so that they won’t mold when you pack them.

5. Once the clumps are dry you’ll need to wrap them so that they are surrounded by dry newspaper, peat moss, sawdust or potting mix. No matter what you use, it needs to be dry. You can put 3 inches of peat moss etc at the bottom of a paper bag, add the tubers and then fill the bag with more of the peat. Or you can roll the clumps in several layers of newspaper, one clump per bundle, and put those bundles in a paper bag or cardboard box. Do not place the tubers in a plastic bin or bag…they are likely to mold.

6. Store the boxes or bags of tubers in a place where it is cool but doesn’t go below freezing. A floor of a cold basement is usually good, or on shelves that are above in an unheated garage.

7. Bring out the tubers in mid-May when the night temperatures are above 50 most nights – separate off individual tubers that have a sprout on them (carefully so you don’t break the sprout) and plant. Do not replant the entire clump as it will grow too congested and the plants and flowers won’t be as large as a result.