(Editor's Note: This article was originally published on March 1, 2007)
Not everyone gets to garden year-round and unfortunately I'm one of the unlucky few (well, probably more like unlucky millions) that has to worry with digging up and storing my bulbs (cannas) and tubers (dahlias) from tender perennials at the end of each gardening season. Sure, it would be great to be able to grow dahlias, cannas, gladiolus, and other southern "perennials" year round without being bothered with digging up the tubers, but we're in a zone here that doesn't allow such luxurious gardening privileges. Even if I did live in say, sunny southern California, I don't think I'd be able to adjust to having one continuous growing season. I like to see seasonal differentiations, give me clear lines between winter, spring, summer, and fall.
I will be using bulbs and tubers interchangeably here because the process involved with digging both is the same.
Leaves on dahlias, cannas, and most other tuberous plants will be blackened by the first killing frost, telling you it's time to start digging. Cut the plants down leaving about a four or six inch stem stub.
Rake away any mulch or leaf debris, this will allow a clear digging area around the plant. Using a digging fork or spade, insert it deep into the soil at least eight inches. Gently pry back on the fork to loosen the soil. Repeat this process around the plant. When you make the last insertion, prying back on the fork should release the plant with the clump of soil. Taking hold of the stem stub, gently lift while prying back on the fork until the clump comes free.
Once the clump of soil is free, carefully lift and let it rest on its side. Now carefully remove the soil from around the tuber clump. Take extra care around the tuber, you don't want to damage it. Many tubers have small necks that can easily break, a tuber with a cracked or broken neck probably will not grow.
Now that the hard part is over, gather your tubers and lay them out on top of several sheets of old newspaper, you can do this in your garage or basement. Spread them around, good air circulation is essential for drying. This should take about a week or two depending on your local weather and the humidity of the area where you are drying the bulbs.
Storage containers vary but you want to put them in something that can "breathe", an old basket or cardboard box will do. Line your box with a plastic bag with 30 or 40 holes poked in the bottom and sides, then several sheets of newspaper.
Add a 3-inch layer of barely damp peat moss in the bottom. Set a layer of bulbs on the peat moss, not touching each other. Cover with another 3-inch layer of peat moss and repeat. Tuck several layers of newspaper over the top layer of peat moss.
Set the container in a dark area where the temperature stays around 45 to 50 degrees. If you have an unheated garage or spare room, the temperature there should be about right.
Some basements are heated, so you might want to use a slightly different technique. First, wrap the bulbs in tissue paper before placing them in the moss, and then use old Tupperware containers with holes punched in the sides. Snap the lid on and you're done. The plastic container will hold a little extra moisture.
Either way you store them, it's important to check the bulbs periodically throughout the winter months to make sure they're not drying out or rotting.
Do you really want to go through all of this when you can buy new bulbs fairly cheap? Well, you'll have to answer that question for yourself. I would wager that there's a pretty large population of gardeners with gumption out there that see this yearly "chore" as a way to lengthen their gardening seasons, especially us unlucky millions living in the northern climes.