Garden editing seems to peak in September. Shorter days and cooler nights are signals to perennials that it is time to slow down growth and prepare for colder weather. Many plants will be ready for a cut back soon. Fall is a great time to dig and divide spring and summer flowering perennials.
Dividing perennials promotes heavier bloom and creates space between plants in the garden by controlling their size. Perennials that benefit from being divided every two to three years include astilbe, heuchera, shasta daisy and tall phlox. Daylily, echinacea and hosta should be divided every three to five years.
Peonies rarely need to be divided but they sometimes do require lifting. Peony buds should be just below the soil surface and may become too deep over time under layers of leaf litter, bark mulch and the like. Lifting the plant to the proper depth will increase performance and flower production.
Fall digging and dividing of perennials should be completed three to five weeks before the ground freezes to allow the plants ample time to root in before winter.