Add new plants to the garden. Fall is the ideal time to plant new additions in your garden. It's a less stressful time for plants to get established, allowing for a spectacular show the next year. September and October are ideal months to plant herbaceous perennials, while November and December are ideal for trees and shrubs. Plant perennials before we have a hard freeze to allow them to take root before cold weather causes the plants go dormant.
Plants are more likely to survive a hard winter if planted early in the fall.
Keep in mind that October is typically the driest month in Tennessee, so be sure to water frequently and adequately. Divide overgrown perennials. Use a sharp spade or shovel to divide into portions you may wish to transplant, give away or discard. When you replant the division or transplant, be sure to cover the exposed root with loose soil and to apply mulch around its crown to help hold in moisture and insulate it. Also, don't forget to water for the first week or two to prevent drying out and to ensure speedy root establishment.