Control Cabbage Aphids
The little caterpillars that eat leaves of cabbage family crops usually disappear about now, but they often are replaced by gray-green cabbage aphids. Check stem crevices and leaf undersides frequently for clusters of aphids, and spray affected plants with insecticidal soap at the first sign of trouble.
Sow Crimson Clover
Whether you sow it for show or for soil improvement, there is probably a place in your yard for crimson clover. It's a great winter cover crop for the corn patch, and I've even used it to create a pretty ribbon of red down my driveway, interspersed with tall yellow snapdragons.
Whether you have stiff-stemmed Shasta daisies or common ox-eyes, this is a great time to dig and divide daisies. Reset the crowns right away after digging them up and breaking them apart. Then provide water as needed to keep the soil moist for a week after transplanting.
If you haven't fed your fescue lawn yet this fall, do it now. The next few weeks are the strongest season of growth for shade-tolerant turf-type fescue, so it's also important to keep leaves raked up so they won't block light to the grass.
You can grow strawberries as an edible ornamental groundcover, plant them in rows, or plug them into containers. Strawberry plants set out now should bear heavily next spring, provided they are adequately fed and mulched with an acidic organic material such as pine straw.