Several plants we grow outdoors during the summer store food in bulbs or tubers (thick, fleshy roots) to survive a dormant period, which may be a dry or a cold season in their native environment. These can be stored over the winter to grow again next summer.
Calla lilies have been readily available for purchase the last few years. These plants are native to South Africa, going dormant in the dry season. They can be grown as houseplants if they receive lots of light, or they can be planted out for the summer in sun or bright dappled shade. They thrive in pots and planters, and even in the ground.
Once night temperatures drop into single digits, they need to be brought in for storage. If they are in pots they can be stored in the pot. Cut off the leaves and allow the pot to dry out to prevent rot, then store in a cool, dark place – a cool corner of the basement or crawl space that does not freeze will do.
Calla bulbs can also be dug out to store. Cut off the leaves and dig them out of the planters. I spread them out on newspaper and allow them to dry in the basement. When they dry the skin toughens and the roots and remaining leaves can then be removed easily. They can be stored in vermiculite in a cool, dark place. I like to use veggie bags for storage because they breathe.
Canna lilies originate from tropical Asia. They also need to be brought in when night temperatures reach the single digits. Cut off the foliage a few inches above soil level. Cannas can also be stored in the pots in a cool, dark place once the pots have dried a bit. If they are in large planters or storage space is limited they can be dug out carefully. Allow the roots to cure a bit and then remove the remaining soil. Store the roots in barely damp peat moss in plastic bags in a cool, dark place. Check them for rot occasionally during the winter. Remove any rot and allow the wound to dry, then store again.
Gladiolus corms are easy to overwinter. Cut off the foliage a couple of inches above ground level and dig out the corms. Spread them out on newspaper and let them dry for 2 or 3 weeks in a warm location. When dry you can easily remove the old corm at the base and the remaining foliage. Store in paper bags in a cool, dry location.
Temperature for storage for bulbs and tubers should be between 4 and 10C. Next topic will be storing begonias and dahlias.