them. After a killing frost, cut the foliage back to 2 to 4 inches above the ground. Lift each clump separately with a spading fork and gently brush the soil off the clump of tuberous roots. Spread the clumps in a well-ventilated, shaded area to cure for a few days. (Do not leave the tubers in full sun) Pack each clump upside down in a ventilated box or basket using slightly damp vermiculite, perlite or peat moss to cover the clumps. If you grow more than one variety, make sure you label them! Ideal storage temperatures are 35 and 50 degrees. Take a look at them every now and then and if they're starting to shrivel, sprinkle lightly with water.