Although a clump of dahlias looks like multiple fingers, you can't just separate the fingers and grow more plants. Each dahlia division needs to have at least one eye and a nice, fat tuber. The eyes are the white or pinkish dots on the tubers. They are the growing point, the place where the stem will come from next year. Dahlia eyes are all located around the base of the stem. The tubers growing off of tubers will not have eyes and will never grow into plants. They can be left on the plant ... MORE for extra food or composted. The big, central tuber is the original that you planted in the spring. It might have another good year left in it, but many gardeners prefer to start with fresh divisions each year.