Sometimes it’s easier to see where to divide if you wait until spring and divide just prior to planting. Dahlia tubers form a sort of wagon wheel shape with the main stem protruding out of the middle. Each section is capable of producing a new plant, providing it has an “eye.” You’ll see the bud begin to swell in the spring, and will be able to tell where to cut based upon the position of the eye. Look for it near the top of the tuber near the stem. Cut above the eye. Each tuber with an “eye” can be cut away from the main stem.