Fall is the ideal time to look over the perennials and note which ones are crowded, which are overgrown and which ones are in the wrong spot. Fall is the best time to transplant and divide the plants, as the cooler temperatures put less stress on the plants. Plants moved in the spring are trying to put out new root growth at the same time they are trying to produce leaves and maybe flowers. This puts a lot of stress on the plant, and many simply succumb. By doing the planting in the autumn, it removes this stress. The root system is established in the fall before the frigid winter temperatures come. During mild spells in the winter when the ground thaws, the perennials will continue root growth and when spring finally comes the plant can emerge with fresh vigor, ready to grow and bloom. Fall planting essentially helps you gain almost a full season on establishing new plants.

Division is necessary for many perennials to keep them vigorous and healthy. Veronica, Coneflower, Coreopsis, Lychnis and Salvia are some plants which need to be transplanted fairly frequently to keep them strong. Indeed, some of these may die out after two or three years if not divided and transplanted at least every other year.

Other perennials rarely need transplanting. Peonies, daylilies, heuchera, geranium and astilbe belong in this group. But even these need it occasionally. Dividing the perennials has the nice advantage of giving you more plants either for your garden, or to give to friends for theirs. An established plant should give you at least four new plants, and maybe many more.

Fall cleanup in the perennial garden should always include listing some perennials to divide and transplant. Getting them established in the fall will pay dividends in the spring with bigger, less stressed plants trying to do too much in the spring. The extra plants generated can plug up holes in your beds, or make wonderful gifts for family and friends. So get out the shovel and start digging!