Dig up Dahlia tubers to save them for next year

Q. How can I save my Dahlia tubers for planting next year?

A. Dahlias should be dug once the leaves become darkened by frost. On a sunny day, cut the stems back to 4 or 5 inches and carefully dig the roots with a fork or spade. Remove the foliage and leave a three to four inch stem. Gently remove all soil from the roots, and leave them in a shady area with good air circulation for a few days. Afterward, give each tuber a very light dusting of sulfur to inhibit fungal disease.

The traditional method of storing dahlia tubers is to place the tubers in shallow boxes filled with dry peat moss, sawdust, vermiculite or sand. Store in a cool, moderately dry area where temperatures are between 35 and 45 degrees such as a basement.

Providing the proper temperature is critical. At warmer temperatures, the tubers can sprout or rot. At colder temperatures, they can freeze. Periodically, check the tubers to make sure they have not dried out and shriveled. Sprinkle with water if necessary.

The American Dahlia Society offers another a method using plastic wrap. Wrap each sulfur-dusted tuber in plastic wrap, and store in shallow box.

Society members report more success in overwintering dahlia tubers with this method, plus you do not have to check the tubers during the winter as is required with the traditional peat moss/vermiculite method.

• Provided by Mary Boldan, University of Illinois Extension Master Gardener. Send questions to Ask a Master Gardener, c/o Friendship Park Conservatory, 395 W. Algonquin Road, Des Plaines, IL 60016, (847) 298-3502 or via e-mail to cookcountymg@sbcglobal.net.