Fall Article
WINTER CARE FOR SUMMER BULBS
By Dr. Leonard Perry
Extension Professor
Dahlias. Cannas. Gladioli. You don't have to bid adieu to these delightful summer perennials just because the growing season is drawing to a close. It's easy to overwinter these and other cold-sensitive perennials that grow from bulbs, corms, and tubers.
How do you do it?
Most tender plants need to be brought in before the first killing frost. In the north country this can be anytime from mid-September to October. Listen to the weather reports. You'll know when the killing frost strikes--all the foliage will turn soft and black.
For cannas, tuberous begonias, and other plants that you've grown in containers, the procedure is easy. These can be stored indoors over winter in their pots. Just check for insects or plant diseases before bringing them into the house. Once the foliage dies back, trim the plants back to just above the soil line. Place in a cool, dry place with good air circulation.
For plants in the garden, start by cutting back the foliage to a few inches above ground. Then, with a spade or other digging tool, carefully loosen the soil around each plant about six to eight inches from the crown of the plant. Dig deep enough to get below the plant, taking care not to scrap, gauge, or otherwise cause a wound as this may expose the plant to infection.
If you accidentally cut the plant's storage system, which is what the bulb, corm, or tuber really is, allow it to dry out so a scab will form before putting it in winter storage.
Allow the bulbs to air dry for a day or two before storing. Carefully brush off the soil, which may harbor diseases. Refrain from vigorously scrubbing or washing off the caked-on soil as this may cause damage. Spread out on newspapers or trays in a warm, dry location.
Place the corms, tubers, or bulbs in a paper bag. Add a handful of slightly dampened peat moss to help prevent the plant parts from drying out. Do not overfill the bags to give the plant materials room to breathe.
Do not use plastic bags. Moisture will build up inside the bag, causing rot. It is okay to use mesh bags (like the kind onions come in) or string bags although good air circulation should make it unnecessary to add peat moss.
Mark your bags according to variety, then place in a cool, dark place for the winter. A basement or garage is ideal, provided it does not get too wet or cold. Temperatures between 45 and 55 degrees F are preferred.
Check periodically in winter, dampening the peat moss if bulbs are drying out or shriveling. Discard any that are showing signs of decay, such as soft spots or rot.
Next spring, remove and carefully brush away any remaining soil. Plant according to directions. Follow this procedure every year for extended enjoyment of your favorite tender summer perennials.