I have promised two people some tubers from our red dahlias when we dig them up this fall. That digging will come shortly after the first frost. One of the two knew the correct technique for saving her dahlias but simply forgot to do it. The other thought that dahlias should survive outdoors in the winter – which they would in agricultural Zone 7 or warmer, but not in the Zone 5 of coastal Maine.

Storage is an important part of gardening – and I am not even going to get into canning and freezing or figuring out where to keep your equipment like hoes, spades, rakes and wheelbarrows. What I will discuss here is where in your own house or apartment you can store unprocessed products of the garden.

Count tubers among these products. While we grow dahlias for the large, gorgeous blossoms they produce from late July until the first light frost, underground the plants are producing more tubers, also called bulbs, each year.

Cut the foliage back to a couple of inches above the ground before digging. Then dig attentively – I use a spading fork – being careful not to damage the tubers. Some people recommend rinsing the tubers with a hose once you’ve got them out of the ground, but I just brush the soil from them. Store them for a week or so to ensure they dry out, making sure temperatures stay above freezing where they are stored. I spread them in a single layer in our shed or garage, but people who have a lot more time than I do say you should hang them upside down.

Once they are dry, put the tubers in containers that provide some air circulation. We have old milk and soft-drink crates that work well; any that don’t fit go into cardboard boxes. Some people cover them in peat moss, but that seems like too much work, plus I worry about the sustainability of peat. I store the boxes in the corner of our basement farthest away from the furnace, where the temperature stays in the 50s. Apartment dwellers and others without basements will have to settle for an unheated closet, which should be cooler than the rest of the house.

Gladiolus bulbs get a similar treatment, although I usually dig them up earlier than the dahlias because they stop producing blossoms and the foliage browns before the first frost. These bulbs produce tiny corms, small bulbs that show up beside the ordinary-sized ones, which if you plant next year and let them grow will get larger in successive years and eventually produce flowers of their own. I store the gladiolus in cardboard boxes next to the dahlias. Because the two are planted the same time in the spring, storing them together makes it convenient for us come planting time.

That corner of the basement will share space with their edible garden neighbors, winter squash. It’s best to pick the squash before a hard freeze, but they will take a light frost. Any squash you store should be unblemished, not easy for us this year because squirrels and/or chipmunks have been nibbling; fortunately, they’ve only managed to make tiny holes in the skin of the squash. Let the squash cure for seven to 10 days in a warm, sunny spot before moving them to a dark area with a temperature of about 50 degrees.

Hang onions in mesh bags from the basement ceiling, where the temperature is slightly warmer. For more information, read my Aug. 15 Grow column.

Next come the root-cellar vegetables. These are vegetables that could be stored in a refrigerator if you had the room, and include potatoes, carrots, beets, leeks, Brussels sprouts, broccoli and apples. Every fall, I turn our basement bulkhead into a root cellar, using information I learned more than a decade ago in a University of Maine Cooperative Extension course. Shortly after we moved into our house, we installed wooden swing doors, built by my father-in-law, to separate the bulkhead from the rest of the cellar as an energy-saving measure. To turn the bulkhead into a root cellar, we put 2-inch-thick Styrofoam panels at the space’s ceiling level. The doors keep out the warmth of the cellar, while the Styrofoam keeps the freezing outside air away from our crops.

We put potatoes in boxes or pails. Carrots can be buried in sand. I’ve never tried storing leeks before, but this year I plan to put them in five-gallon pails and surround them with a bit of soil.

Put in a five-gallon pail of water in with all the vegetables. The water will freeze before the vegetables do, preventing any harm to them. Water freezes before the vegetables for the same reason that lake water freezes before the ocean – the salt in the vegetables lowers the freezing point. Also, according to the Cooperative Extension educator who taught my course, the process of the water freezing slows the cooling of the air, in turn preventing the temperature of the air in the root cellar from dropping low enough to freeze the vegetables. I didn’t take enough science courses to know why this works, but it does.

Still, despite the pails, I open the wooden doors a crack whenever the forecast predicts temperatures going down to single digits. I’ve been accused of being a belt-and-suspenders type of person.

Tom Atwell is a freelance writer gardening in Cape Elizabeth. He can be contacted at: tomatwell@me.com.

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