Most of us have experienced at least a light frost in our gardens at this point of the season. There’s nothing like frost on your car’s windshield to put a sense of urgency into the gardening chores in October. To delay is folly.
If you have any of the so-called “tender” plants; dahlias, gladiolus, canna lilies or tuberous begonias, they must be lifted out of the ground before the frost goes too deep and then stored indoors over winter.
Some of you who previously lived in warmer climates than ours may have just left these plants in the ground to overwinter. We have no such option, even here in the sunny Okanagan. Dig them up soon or they will freeze and turn to mush, a most unpleasant sight I can assure you.
I’ve heard from more gardeners each spring that have either forgot, or consciously left, their gladiolus corms in the ground, and have had them survive. It depends on the site, and on the winter, but I think you’re living on the edge if you don’t lift them.
As soon as the foliage yellows, after a light frost or two, cut off the foliage just above the corm and set them to dry for a few days. Clean off the soil, rub off all of the little bulblets which have formed and take off the old, withered corm from which the new corm has sprouted. Store them in a cool, dry and well-ventilated location,
The foliage of dahlias is very sensitive to frost; it dies down rather abruptly after a sub-zero night. The routine is the same as for glads. Cut down the foliage to just above the tuber, lift them out of the soil and then let them dry for a couple of days, removing any remaining soil.
Dahlias can be stored in slightly moist peat or vermiculite. If stored too dry the tubers will shrivel and lose strength for next year. Too wet, and ugh! Rotten tubers. Keep checking on them through the winter to make sure they’re in good shape.
Tuberous begonias should be lifted now. If the foliage hasn’t been frosted yet just cut it off. Canna lilies are terrific summer flowering and foliage plants, ideal for mass planting in larger flower beds or in containers. They can easily be wintered if treated in the same manner as these other plants.
If you’ve never stored bulbs, corms, tubers or rhizomes and are unsure about location, take a look around your home. An unheated porch, a cool spot in the basement, a storage room; any of these will do as long as it’s cool (but not freezing) and dry.
Peat moss is an ideal material for storing your bulbs. Its moisture content can be easily manipulated and it’s light and easy to use. Cardboard boxes make good storage units.
If you have a collection of many glads and dahlias and want to avoid colour roulette next spring be sure to label everything for colour, height and other pertinent information.
By properly storing these tender plants this fall and through the winter you can ensure a good start to next spring’s flower show.