Plant Cool-Season Annuals
Rejuvenate gardens by planting cool-season annuals. Snapdragons, calendulas, pansies, dianthus, and flowering cabbage and kale are good choices. Seedlings are widely available, and the flowers will last well into fall. Replace tired summer annuals in containers, too.
Add Fall Flowers
If your gardens are winding down, consider adding fall-flowering perennials to your landscape. Chrysanthemums, asters, joe-pye weed, ornamental goldenrods, and sedums are all good choices. Trees and shrubs with attractive fall foliage and interesting bark will extend the interest into winter.
Begin dividing overcrowded perennials. Phlox, iris, Shasta daisies, and daylilies, for example, all benefit from dividing every few years to keep them growing and flowering vigorously. Replant divisions in a new bed or give them away. Signs that plants need dividing include reduced flowering and poor growth at the center of the plant.
Gather Materials for Fall Arrangements
Gather ornamental grasses, seed heads, pods, and other natural materials for dried arrangements. Gourds and sumac seedheads are also attractive in decorations. Air-dry by hanging in a dark, well-ventilated location.
If there are areas in your yard where lawn grass struggles, consider replacing it with something that will thrive. In shaded areas, for example, woodland plantings of ferns, hostas, and other shade-lovers will thrive and need less maintenance, too. On difficult-to-mow slopes, consider a mass planting of daylilies.