October's The Time To Dig And Store Summer Bulbs
The difference between hardy and tender bulbous plants is a matter of
geography, not underground structure. Plants originally developed bulbs,
corms and tubers to help them survive conditions like cold and drought.
In cold-climate gardens many tender bulbous plants which can't survive
extremely low soil temperatures can be lifted and brought indoors for
their winter's rest. Some of the varieties commonly lifted and stored
indoors in New England are tuberous
begonias, dahlias, cannas, caladium and gladiolus.
These tender summer bulbs should be removed from the garden after they have finished growing for the season and before the ground freezes. It is extremely important that care be taken in handling to avoid bruising them. Bruised or cut surfaces provide an entryway for disease organisms which can cause bulb rot. During the digging process be careful to avoid spading fork or shovel injury since each cut or bruise provides a possible site for infection. Once in storage you will need to check bulbs periodically and remove those that show signs of rot or decay.
Tuberous begonias need to be stored before the first frost. Gradually reduce their water supply when the foliage begins to turn yellow in the fall. When the foliage has died down completely, stop watering altogether. Then gently remove the main stems. If removal is difficult leave them a few more days and then try again. When the tubers are completely dry and dormant, dig them carefully. Dry the tubers before storage by spreading them out in flats and placing them in the sun or in a dry, well-ventilated site. After about two weeks, store the tubers in a single layer on trays in a dry, cool place. If at all possible, the winter temperature should remain around 45 to 50 degrees fahrenheit. You can leave the bulbs uncovered, or sift dry sand or peat moss between them and very thinly over them.
Dahlias, like tuberous begonias, are extremely sensitive to cold. Their tops will be frozen and blackened by the first hard frost. After this happens, cut the stalk to within 6 inches of the ground and allow the plants to remain for a few days to cure and become dormant. Then dig the tuberous roots carefully, and place them in the sunlight for a day to dry. Gently brush away any dried clods of soil. Dahlias should be stored between 40 and 50 degrees fahrenheit. A covering of dry vermiculite, sand, peat moss or rice/peanut/buckwheat/cocoa hulls will prevent the loss of additional moisture and damage to the roots from excessive drying.
In Victorian times cannas were used for formal bedding. Today's modern varieties have become increasingly popular with their compact foliage and showier flowers that bloom earlier in the summer. Cannas now add a touch of the exotic to many a garden. For winter storage they are treated much the same as dahlias. The rhizomses are dug after the frost kills the tops, they are dried in the sun for a day, clinging dirt is gently removed and they are stored in a cool, moderately dry place. Cannas should be packed in dry vermiculite, peat moss or one of the hulls mentioned above.
Caladiums or "dancing ladies" make a lovely summer show with their heart-shaped leaves (pink, red, white or green) dancing in the breeze. They are very well-adapted to our hot, humid August days, but the tubers are tender. For winter storage treat them as you do dahlias or cannas, but keep them a slightly warmer temperature (55 - 60 degrees fahrenheit).
You can prepare gladiolus for winter storage by cutting the leaf stalks to about 2 inches above the ground when the foliage turns yellow. Then lift the corms with a spading fork. Cure by spreading the corms in a flat and placing them in a well-ventilated location for several weeks. After they are dry, remove the roots and the remains of the old corms from the previous season's planting. Separate the new corms and the small cormlets and spread on a shallow tray. Store between 40 and 45 degrees fahrenheit with a relative humidity of 80 percent. Gladiolus do not need to be packed away in sand or any other dry medium, you can simply hang them in "bags" of panty hose in a place with good air circulation. In the spring your cormlets can be planted in the vegetable garden to develop size for one or two years until they are large enough to bloom.
Suitable locations for storage include a root cellar or a cool corner in the basement, or a shed or garage where temperatures remain between 40 to 60 degrees fahrenheit. Don't guess at temperatures; keep a thermometer handy, The closer to 40 degrees the better to prevent drying our or sprouting. It's also a great luxury if you have an extra refrigerator just for storing bulbs!
Call the UNH Cooperative Extension's Family, Home & Garden Education
Center 's Info-Line toll-free at 1-877-3984769 for "Practical Solutions
to Everyday Questions." Trained volunteers are available to answer
your questions Monday through Friday from 9 am to 2 pm .