Dahlias: To Dig or Not to Dig

Dahlias are considered tender perennials and as such they need to be protected from the winter cold. Many tender perennials survive very well left in the ground when provided with a thick layer of insulation from straw, leaves or mulch. Others need to be removed from the ground and stored in a cool dry area.In most northern climates, Dahlias would fall into the group of those plants that need to be removed. Left in the soil they are susceptible to excess moisture and may rot or freeze. Wait to dig until after a killing frost. This allows the plant to produce the maximum amount of food stored in this “tuber” (it actually is a tuberous root) for beautiful growth the following year. Cut the tops back to a few inches. Carefully lift out of the soil without damaging the tubers.

Store in a cool location with temperatures around 50 degrees F. Storing in coarse vermiculite will help to maintain enough moisture to prevent the tubers from shriveling but not enough to cause them to rot.

You can find this article (by Mary Conklin) and other useful gardening articles in the Oct-Dec, 2011 issue of Bloomin ‘n News at http://extension.psu.edu/montgomery/programs/master-gardener.

Curious about the differences among tubers, tuberous roots, bulbs, rhizomes, and corms? Then visit http://www.pcmg-texas.org/BulbsCormsTubers.pdf. For other gardening questions in Lackawanna County ask for the Garden Help line at 963-6842 or email LackawannaExt@psu.edu.


Terry Schettini, Extension Educator
Penn State Cooperative Extension in Lackawanna County