Dahlia growers are passionate about how dahlia tubers should be stored. In past years I would leave the tubers in their original clumps (marked with their name) and stored in either peat moss or cedar sawdust. In the spring I would divide the clumps. I had to be very careful to keep the tubers from drying out.
I have become much wiser in how to deal with dahlia tubers. First, after the first frost I cut down each dahlia plant, leaving an eighteen inch stalk sticking up out of the ground. Survey tape is tied to each stalk with the name of the dahlia written on it in permanent marker. Leave the tubers in the ground for at least ten days before digging up the tubers—this allows the eyes to enlarge, making the dividing of the tubers much easier.
After the tubers were divided they were wrapped in plastic wrap. Place a tuber on the plastic wrap and then have one wrap of the plastic around the tuber. Then, place another tuber with the first tuber and have one wrap of the plastic around the two tubers. Continue until there are eight to ten tubers in the bundle. Only one type of dahlia tuber is in a bundle. Mark the bundles with the type of dahlia and the number of tubers in it. The plastic keeps the tubers apart so that if one tuber rots the other tubers are protected.
I have packaged 91 tubers for our church’s garage sale and found only two tubers that were rotten. I have checked most all of the bundles and there appears to be little if any loss. I am very please with how this storage system works.
I placed cedar sawdust in the bottom of a box, put in a layer of tuber bundles, added a layer of cedar sawdust, etc. until the box was full.