Coastal and Tropical South
Unless you're completely happy with your lawn (and hardly anyone is) now's the time to apply a winter conditioning fertilizer. Use a spreader that rotates, rather than a drop spreader, for even coverage across the whole lawn. Fill the spreader over a driveway, so a spill doesn't overfeed the grass.
Cover Exposed Tree Roots
When tree roots grow old and large, they are often near the surface and may break through lawns, or rise when the soil around them erodes. Fill in the spaces between the exposed roots with good garden soil, but don't put more than one inch on top of any root.
Refresh the Weary Ground Covers
Ground covers like leafy Vinca major, and even rugged Asiatic jasmine, can look worn out in August. With plenty of time yet before frost, go ahead and give them a light trim -- take just a few inches off the top. Use a low-nitrogen fertilizer to give them a boost without overfeeding them.
Fertilize Yellowing Azaleas
Late summer can be rough on many shrubs, and azaleas may develop a condition called interveinal chlorosis. It simply means the veins of the leaf stay green, but the rest of the leaf is yellow. Iron is the usual remedy. Products can be sprayed, drenched, or sprinkled, but be sure to water the plant first.
Tend to Overgrown Water Gardens
Water lettuce, pickerel, and other rapidly growing water garden plants can get way out of bounds in late summer. If your surface plants are covering 90 percent of the water, remove enough to get that number down to 70 percent to restore balance. Start a colony in a container -- for that new pond you'll build this fall.