Bulbs - Digging and Storing Non-Hardy Bulbs

In order to preserve your favorite dahlias, cannas, tuberous begonias and gladiolus for planting next spring, you'll need to dig and store them in a frost-free area for winter.

After a damaging frost, cut the tops of dahlia plants back about 1-2 inches above the soil. Before the ground freezes, dig the roots from the ground being careful not to damage the crown area. Wash gently with a hose to remove excess soil. Cure 1-3 days in high humidity to avoid desiccation. Tubers can then be stored in shallow boxes in a moist medium such as vermiculite or sphagnum peat. Division is best done in spring when buds are more evident. (The buds are located in the crown area and each division must have at least one bud with tubers attached.)

Canna stems should be cut to 2-3 inches after a damaging frost. Dig the rhizomes carefully to avoid damage that may cause rotting. Wash gently with a garden hose to remove excess soil. Cure 1-3 days in a shady, well-ventilated area, and then store in shallow boxes with vermiculite or sphagnum peat.

Dig tuberous begonias when the foliage starts to yellow or after a frost. Cut the stems to about 5 inches. Allow tubers to cure indoors at room temperature, out of direct sunlight until the stems are dry and loose. Pull off stems and any roots or soil, but do not wash the tubers. Store in a perforated plastic bag filled with peat moss or vermiculite. Store in a cool, dark place.

Cut gladiolus tops back, leaving no more than an inch or so of stem. Remove excess soil from the corms but do not wash them. Spread the corms out in a dry, well-ventilated place such as a garage for 2-3 weeks. Once dried thoroughly, remove and discard the old corms and stems. The healthy new corms are then ready for storage.

Dig these tender plants carefully with a garden fork. Damaged roots, tubers, rhizomes and corms do not store well. The ideal storage temperature range is 40-50º F, much cooler than most modern basements. A spare refrigerator can be an ideal place to store tender bulbs.