Coastal and Tropical South
Crpe myrtles and dogwood seem to be first up this year for our regions' subtle notion of "fall color." But their display may not be entirely seasonal. Waterlogged roots cause plants to stress, causing leaves to concentrate their nutrients back into the stems for survival. This translocation causes the leaves to color up, and then drop. Prune the affected plants back a bit next spring.
Rake and Mulch
Garden sanitation takes center stage this month, and cleaning up now can prevent problems later. Cut down the weeds, rake the leaves as they fall, and rogue out the invasives like jewels of Opar that you can't stand to kill completely. Then put a new layer of mulch over the whole garden. As the inevitable weeds emerge, keep them under control.
Help For Weak Trees
0-20-20 is a fertilizer formula we don't use enough, but should consider, especially in early fall. If trees have weak limbs, or just aren't growing, if shrubs haven't put on much new growth for several years, try 0-20-20. A no-nitrogen formula can nourish roots without pushing top growth. You may have to ask at the farm co-op for this formula; they seem to be more familiar with it.
The glory that is glossy leaf hibiscus can get a bit ragged this time of year. Plants may be overgrown, have a few bugs, or even stop blooming. Prune out any damaged areas and then shape the rest of the plant to compensate. Cut otherwise healthy hibiscus that are not blooming back by about one third right now, fertilize with a flower formula, and watch for new leaves now and flowers by November.
It may feel early, but go ahead and plant lettuce seeds now. Pick a spot in the flowerbed or vegetable row that isn%t in full sun. Work the soil well and rake very smooth, then sow seed on top. Press in, but don%t cover. Use a floating row cover for best results. If you grow in containers, plant a few half full of lettuce, but leave room for chives or pansies, too.