Some plants have fleshy roots or stems that can be cut into sections, so that a new plant grows from each section. This is called division . These stems and roots have special names. The crown of some plants is the part near the surface of the ground from which new shoots come. When the clump gets large, it can be cut apart.
Rhizomes are underground stems.
Tubers , like Irish potatoes, are swollen, underground stems that store food. Roots like dahlia and sweet potato store food too. Each of these is treated differently. After roots form, it can be cut free and planted. Layering usually works best in spring or late summer.