Mid-August might not pop to mind as a prime planting time, but for several important vegetable crops and for three popular annual flowers, it's their turn for the spotlight.You'll find the various "cole" crops at the top of the mid-August vegetable planting list. Cabbage is the most popular, but the list also includes broccoli, cauliflower and Brussels sprouts. All thrive in fall's cooler weather. In fact, all are capable of withstanding light freezes prior to harvest. But they need to be planted now.The biggest challenge in growing these plants in the fall might actually be in finding the transplants. You'll want fresh and vigorous plants of well-suited varieties, and your best chance of finding them now will probably be through local independent retail garden centers and feed stores.Set the transplants into well-prepared garden soil. All of them will need 18 to 24 inches of space between plants within their rows, and the rows should be 36 to 42 inches apart to permit easy access. If you're careful to select transplants that have been in full sun in the nursery, setting them into the garden now should present no problems. Plant them into small "wells" an inch or two deep to facilitate watering. Soak them every day for the first week or two, to allow them time to develop good roots.Cabbage loopers are the bane of our spring cole crops. The larvae chew multitudes of holes in the leaves. They render cabbage useless as a leafy vegetable, and they weaken the growth and productivity of the other types. They'll probably also find your fall plantings, so be on the lookout for the white butterflies that serve as your early warning signal. They seek the cole crops and lay their eggs on the leaves.As soon as you see the horseshoe-shaped caterpillars starting to feed, apply the biological worm control Bacillus thuringiensis, known more commonly simply by its initials, "B.t." It's available as a dust or a spray, and it's the only control, organic or inorganic, that works on these pests. It stops their feeding immediately, and they will die within 24 hours. It can be applied within 24 hours of harvest.Fertilize all of these crops with a high-nitrogen food similar to one you might use on your lawngrass. Most of our soils test too high in phosphorus (middle number of the analysis) anyway, so nitrogen will be the prime need.As for other vegetables that remain to be planted, that list would include leafy and root vegetables such as lettuce, spinach, chard, beets, turnips, collards, carrots and radishes. All of those are planted closer to the end of August.People within the urban heat pocket of Fort Worth and its suburbs can usually push the planting dates back by a week due to their somewhat warmer late-fall temperatures. And, just to have stated it, you're too late to plant tomatoes, peppers and probably even squash, cucumbers and beans. That depends, of course, on where you live and on the date of the first freeze this coming fall.Flower plantings for mid-AugustThree types of annual flowers will perform far better in the fall than they did in the spring. Marigolds, zinnias and celosias benefit from the cooler temperatures associated with September and October here in North Texas.Marigolds traditionally fall victim to spider mites in our spring plantings. As soon as it begins to turn warm in late May and early June, the nearly microscopic pests start to suck the life out of the marigolds' leaves. The leaves are finely mottled, and they soon turn tan and crisp. But, that's spring marigolds. Fall marigolds almost never crop up with spider mites. Adding to the bonus, fall marigolds also have deeper, richer colors, and they'll keep blooming right up to frost.Zinnias don't get spider mites, but powdery mildew often wrecks them in late spring and early summer. Granted, there are mildew-resistant hybrids that also handle the heat, but fall plantings of all types are going to be showier. Most noticeable of all: Fall zinnia colors are two shades deeper and richer than those of the same varieties in late spring and summer.Celosias (cockscomb) do famously in fall. They're not shabby in spring, but the red-flowering types especially become September superstars in Texas gardens. Not only are their flowers a rich maroon red, but so is the foliage. In fact, the old reseeding heirloom cockscomb is unbelievably showy in fall.All three of these plants should be bought in 4-inch containers. You want to choose plants that are vigorous and that are in bud, but not yet in flower. Transplants that have already matured their first round of blooms usually stall out after planting, while the others establish quickly and kick into flower for the next 90 days up to frost.Check with your favorite nursery soon. Hopefully they'll have just what you need.Neil Sperry publishes "Gardens" magazine and hosts "Texas Gardening" from 8 to 11 a.m. Sundays on WBAP AM/FM. Reach him during those hours at 800-288-9227 or 214-787-1820.