Question: We live near Crossville, Tenn. and will be moving soon. What is the earliest I can dig up my callas? They have survived well the past three winters without being dug up but they probably need to be separated anyway.
Callas are native to South Africa, so there is always the chance that the tubers may not survive extremely cold winter in the ground. But most gardeners I talk to in Middle Tennessee (Zone 7a, home of The Garden Bench) say they never dig up the rhizomes, and they come back each year. In Zone 6b (The USDA Hardiness Zone for Crossville), their survival seems a little less certain, but if yours have continued to grow and spread, then they must be in a friendly environment.
Here’s the recommendation for winter storage from the Gardening Know How website: To dig the rhizomes for storage, lift the clump out of the soil and allow them dry for two or three days, brush off the remaining soil and store them in peat moss in a paper bag in a cool, dry location.
Replant them in their new home next spring, after the danger of frost. Callas appreciate slightly acid soil that drains well, and should be watered regularly while they are growing and in bloom. They grow in full sun or partial shade.
The graceful flower bracts of calla lilies, which open about mid-spring or early summer, are lovely and delicate, but don’t be fooled by this. Callas are sturdy plants, and I have seen them escape their bed and push up through the packed gravel of nearby garden paths.