Preserve the Harvest
Canning, drying, and freezing are all great ways to preserve your garden produce to enjoy this winter. Your county extension office should have the most up-to-date recommendations on how to process your food safely (many older canning recipes are no longer considered safe) and maintain the best possible quality during storage.
If your garden became weedy while you were on vacation, act now. Cut flowers and seed heads off any weeds that are blooming to prevent reseeding. Next, cut or mow weeds as close to the ground as possible, leaving the stems and foliage on the ground. Smother them using several sheets of newspaper topped with organic mulch.
Expand Your Palette
Consider adding some late-season, flowering shrubs to your garden palette. How about caryopteris, landscape roses, butterfly bush, hypericum, crape myrtle, peegee hydrangea (Hydrangea paniculata), and oak leaf hydrangea (Hydrangea quercifolia). Trumpet vine (Campsis radicans) and perennial sweet peas also provide welcome garden color during August.
It's time to start planning and planting the fall vegetable garden. Spinach, beets, kale, kohlrabi, lettuce, and peas grow well in cooler weather and will yield fall crops. Quick-maturing varieties of cucumbers and bush beans can still be planted now as well.
Preventing Ugly Mildew
Mildew on plants such as phlox, monarda, zinnias, and lilacs is ugly but does not usually need to be treated this late in the season. To prevent mildew, give these plants good air circulation and use cultivars with improved mildew resistance. Also do a thorough fall cleanup to limit sources of reinfection.