Digging up the root ball of an established plant completely and cutting it into sections actually benefits the plant.
Your summer and fall gardens will reflect your April efforts. This is our time to move things while they are still small.
Survey your garden and try to imagine it in spring and summer, and identify dead spots and relocate new perennial divisions to those.
It is hard to transplant plants with taproots, so look for small new plants or offsets near an established plant and dig a deep circle around them.
Cool fall days give gardeners the incentive to divide perennials, so that new starts can be established before the winter.