This has been a boom season for powdery mildew, a fungal infection that looks like white powder on foliage of susceptible plants, such as lilac, crape myrtle, roses, bee balm and phlox. It usually will not damage the plants this late in the season, although it looks awful. If this is a problem year after year, consider planting mildew-resistant varieties and improve air circulation.
Repairing the Lawn
Now's the time to overseed sparse lawns, reseed bare patches, or start anew with seed or sod. Fall rains will help the grass establish before winter. Dethatch and/or core aerate if needed, then broadcast seed with a rotary spreader or use a slit seeder. Test your soil first to see if you need to use fertilizer or lime.
Plant Fall Veggies
Keep up with preparation for the fall garden even though it seems like the height of summer. Set out transplants and start seeds for your cool-weather crops, such as carrots, peas, lettuce, cabbage, kale, beets, and spinach. Try for one more sowing of late bush beans.
Plant Blooming Shrubs
If your garden is looking a little blah right now, consider adding some late-summer blooming shrubs, such as: crape myrtle (Lagerstroemia indica, pee-gee hydrangea (Hydrangea paniculata), rose of sharon (Hibiscus syriacus), trumpet creeper (Campsis radicans), or blue-mist spirea (Caryopteris clandonensis). Mark the desired planting location in the garden so you can add them either this fall or next spring.
Edit Your Yard
This is a good time of year to pause and enjoy the yard or garden, especially early in the morning while it is still cool outside. While you kick back and relax, think about what did well or poorly this season, and what you might want to change. Fall is a great time for carefully transplanting (and purchasing) many kinds of plants.