Here the recommendation of Texas A&M AgriLife for the months of July and August: By August many fall vegetable seeds and even small plants may be set out for later production. Be careful to give extra water, and a little shade, to these young plants while they are becoming established. The result will be excellent cool season garden produce.
Trim off faded flowers on crape myrtles and vitex to encourage later re-bloom. Evaluate the volume of water delivered from lawn sprinklers to ensure healthy, stress-free grass during the heat of the summer. One thorough watering which will deliver one inch of water at a time is better than several more shallow sessions. The amount of water available through flower bed sprinklers may be checked by placing several shallow pans among shrubs or flowers. Prune out dead or diseased wood from trees and shrubs. Hold off on major pruning from now until midwinter. Severe pruning at this time will only stimulate tender new growth prior to frost. Sow seeds of snapdragons, dianthus, pansies, calendulas, and other cool-season flowers in flats, or in well-prepared areas of the garden, for planting outside during mid-to-late fall. Plant bluebonnet and other spring wildflowers. They must germinate in late summer or early fall, develop good root systems, and be ready to grow in spring when the weather warms. Plant seed in well-prepared soil, one-half inch deep, and water thoroughly. Picking flowers frequently encourages most annuals and perennials to flower even more abundantly. Pick okra, peas and peppers often to maintain production.It is time to divide spring-flowering perennials, such as iris, Shasta daisy, oxeye, gaillardia, cannas, day lilies, violets, liriope, and ajuga. Make your selections and place orders for spring-flowering bulbs now so that they will arrive in time for planting in October and November. Don’t allow plants with green fruit or berries to suffer from lack of moisture. A late-summer pruning of rosebushes can be beneficial. Prune out dead canes and any weak, brushy growth. Cut back tall, vigorous bushes to about 30 inches. After pruning, apply fertilizer, and water thoroughly. If a preventive disease-control program has been maintained, your rose bushes should be ready to provide an excellent crop of flowers this fall. It is not too late to set out another planting of many warm-season annuals, such as marigolds, zinnias, and periwinkles. They will require extra attention for the first few weeks, but should provide you with color during late September, October, and November. Establish a new compost pile to accommodate the fall leaf accumulation. For more information on this or any other agricultural subject please contact the Hopkins County Extension Office at 903-885-3443 or email me at firstname.lastname@example.org