How to Dig Up and Store Dahlia Tubers
Artist Frances Palmer, well-known for her pottery, is also a passionate dahlia gardener. After teaching us how to plant dahlias, she returns to GardenDesign.com to show us how to dig up and store dahlia tubers for the winter.
Frances Palmer, a member of GARDEN DESIGN's design board, is a well-known potter, a passionate gardener, and a lover of dahlias. Today, she shares with us the second part of her instructional series about how to dig up and store dahlias for the winter.
If you followed Palmer's instructions for how to plant dahlia tubers in May, now it's time to learn how to store the tubers until next spring. (Palmer's first installment also included some of her favorite mail-order sources for dahlias, so if you might want to order some catalogs now, to inspire you for next year!)—Claire Lui
Frances Palmer's garden in September, filled with dahlias at the peak of bloom.
Another view of the garden in September with the smaller pom pon dahlias in front.
[If your dahlias are still in bloom, read our post about arranging with dahlias.]
After the first frost, usually in late October or early November here in Connecticut, the flowers and stems will immediately wilt. Leave everything in the ground for a week or two and after a few more strong frosts have occurred.
Before you start digging the tubers, pull out any supports you used during the growing season, such as tomato cages, stakes, and string.
Using a pitchfork, start to dig outside the circumference of the tubers. The size of the flower will give you an indication of the size of the tubers in the ground. (For example dinner plate dahlias will have larger tubers and pom pon dahlias will have smaller tubers.) The larger the plant, the larger the distance of the tuber from the center of the stems.
Gently push the pitchfork deep down and under the tuber bunch. If one or two get snapped off while pulling up the plant, this is fine and will not damage the plant.
Cut off the dead stems two to three inches above the tuber bunch. This will give you something to hold onto while moving them around.
Here is a dahlia with freshly cut stems. Shake off as much dirt as possible. If, however, some dirt remains stuck between the tubers, this is fine.
If you have used a tag in the garden to identify the variety of dahlia, tie it onto the freshly clipped stems.
Take the tubers to be stored, ideally in a cool basement or garage that is about 40 degrees, but that does not freeze. You do not have to put them away immediately. I usually leave mine in the basement for a week or so before putting them into the boxes for winter storage.
Use a large cardboard box and put a few inches of either peat moss or wood shavings at the bottom. Give the tubers a final shake to release any dirt that has dried. Place the tubers in the box on top of this bed. Put the largest and heaviest bunches at the bottom and work up to the smallest and lightest.
When the box is about midway full, begin to filling in with more storage material (peat moss or wood chips) around the tubers.
Once the box is filled, cover completely with the storage material. Give the box a few good kicks to get the material to settle in and then add more, if needed. Fold over the flaps to close.
I find dahlia flowers gorgeous in the summer and in the winter, I find the tubers gnarled and beautiful.