Not all perennial bulbs are capable of being overwintered in the ground. For gardeners living in northern climates (zone six and below), digging up and storing tender perennial bulbs indoors is an annual task.
But just which perennial bulbs need to be dug up, and how do you do this? Here is a list of some of the most popular tender perennial bulbs, with instructions on how to dig them up and store them over winter:
- Cannas. In the fall, allow the frost to kill off the green foliage, but do not allow the rhizomes underground to freeze. When digging up, carefully lift the rhizome and stem out of the ground and cut off the dead top portion of the plant. Clean off the excess soil and allow the rhizome to dry, then wrap in newspaper and store indoors in boxes or paper bags at 45-50 degrees (F). Replant in early spring once temperatures are over 70 degrees (F).
- Dahlias. These perennial bulbs may be overwintered in the ground in some regions, with sufficient mulch, but for most areas it is much safer to dig the dahlias up before there is a hard freeze. (A light freeze that kills off the top foliage is fine). Do not let the tuber dry out during storage. It is best to overwinter them in some peat moss, checking to make sure they do not get too dried out, and misting lightly as needed. You can plant them back into the garden once nighttime temperatures are above 50 (F).
- Tuberous Begonias. Allow a light frost to kill off the top foliage, but do not let the tubers themselves freeze. Lift carefully from ground, and let the tuber dry for about a week, leaving at least 5 inches of the top foliage on the plant. Store in peat moss or sawdust about 50 degrees (F) during winter months, and then replant in early spring once daytime temperatures are above 60 degrees (F) and all danger of frost has passed.
