Every flower has its headwind, like the rose, its thorns. The dahlia is burdened by the fact that it is neither an annual nor a perennial, but needs to be dug and stored each autumn. I have been engaged with the gardening public for years, and the comment most frequently made is “I do not grow dahlias because they have to be dug.” Fortunately, container dahlias do not have this handicap. Growers seem content to enjoy the blooms for their long season and toss the plant away after frost. Perhaps, this is why they are so widely marketable.
I started growing dahlias in an era when everyone dug, saved, and stored their clumps. Perhaps they were frugal, or more likely adhered to a custom that began in the early 1800s when dahlias first appeared in Europe and the United Kingdom. It is time in the second decade of the twenty-first century that we think more broadly.
-
Treat dahlias as annual flower. Dahlias are so readily available and inexpensive that they can easily be replaced next spring. If you calculate the per bloom cost of a plant, it is usually pennies.
-
Leave dahlias in the ground and hope for the best. If you have soil with decent drainage, clip the stalks and cover the ground with leaves five or six inches deep. They are likely to reappear the following March. I have a friend in the Adirondacks who grows a few dahlias next to his house. He adds some mulch in the autumn, and covers the area with snow as insulation throughout the winter. In Virginia, I add a plastic covering and have had some success. Maybe it is “climate warming.”
-
Dig, divide and store. We cannot ignore tradition. When asked about storing, I respond, "How do you store them?” If their method works for them, I smile and say, “do not change a thing.” I dig the plants I value, cut them up right away, dust the cut surfaces with cinnamon, and pack them in plastic bags with vermiculite, with tags and markings. I store in a plywood closet that holds the temperature at about 50°F. Much information about digging, dividing, and storage is available. See the links below.
