August marks the transition from intense summer heat toward the fall growing season in Texas. Although temperatures remain high, this month is the deadline for starting many cool-weather crops so they mature before the first frost arrives. Planning and planting strategically in August guarantees a productive harvest of vegetables and continued color well into autumn. The heat requires careful preparation, but the rewards are a longer and more abundant growing period in the milder months ahead.
Understanding Texas Growing Zones in August
Texas’s size means August planting schedules vary significantly based on regional climate and the average first frost date. The state encompasses USDA Hardiness Zones from Zone 6 in the Panhandle down to Zone 10 along the Lower Rio Grande Valley.
Northern Texas (Zones 7 and 8a) typically sees the first frost around mid-November. Central Texas (Zone 8b), including the Hill Country, pushes the average first frost to late November or early December. South Texas and the Coastal Bend (Zones 9 and 10) may not experience a frost until late December or January, allowing for the latest planting times. Crops requiring a longer maturation period must be planted earliest in the north.
Essential Vegetables and Edibles for Fall Harvest
August is the starting point for a successful fall vegetable garden, focusing on cool-season crops.
Brassicas
Brassicas are a primary focus. Plants like broccoli, cabbage, and Brussels sprouts should be started indoors from seed during early to mid-August, especially in North and Central Texas. This early start allows seedlings to establish root systems before being transplanted outdoors in September or early October. Cauliflower and kale also benefit from this indoor head start, preventing them from bolting prematurely in the summer heat.
Root Vegetables
Root vegetables are best sown directly into the garden soil around mid-to-late August, as they do not transplant well. Radishes and turnips mature quickly and can be planted late in the month, with successive plantings every two weeks for a continuous harvest. Carrots and beets require a longer development period and should be sown toward the end of August. Ensure the soil remains consistently moist for successful germination. Greens, such as Swiss chard and collard greens, can be direct-seeded in August across all regions of the state.
Warm-Weather Crops
Warm-weather crops planted earlier can often be revived for a final push of production in the fall. Okra and Southern peas (like black-eyed peas) are heat-loving plants that can still be direct-seeded in early August. They mature rapidly and will produce until the first frost. Bush beans can also be planted early in the month for a quick crop. Gardeners in the warmest zones of South Texas can plant a second round of heat-tolerant tomato and pepper transplants in August for a late-season harvest.
Flowers and Herbs Thriving in Summer Heat
Ornamental plants and culinary herbs planted in August tolerate the summer heat while providing color and flavor into the autumn. Annual flowers that thrive in extreme heat, such as Cora XDR Vinca and Celosia, are excellent choices for August planting from transplants. Cora Vinca is valued for its resistance to aerial Phytophthora blight, a disease common in hot, humid Texas conditions. Marigolds are another tolerant option that adds vibrant color and benefits the garden by releasing substances toxic to nematodes in the soil.
For herbs, the focus is on varieties that tolerate high temperatures without bolting or wilting. Basil performs best in August when planted in a location that receives afternoon shade to prevent scorch. Rosemary and oregano are highly heat- and drought-tolerant perennial herbs that can be successfully planted from transplants. Mexican mint marigold, often used as a substitute for French tarragon, is a durable perennial that thrives in the Texas summer and can be planted now to establish itself before the fall.
Irrigation and Soil Strategies for August Planting
Successfully establishing new plantings in August requires strategies to combat high temperatures and conserve moisture.
Irrigation
The principle of deep and infrequent watering is primary for encouraging deep root systems that better withstand heat and dry periods. Instead of daily, shallow watering, a deep soak every few days forces roots to grow downward where the soil is cooler and retains more moisture. Drip irrigation or soaker hoses are the most efficient delivery methods, applying water directly to the root zone and minimizing loss to evaporation. Irrigating in the early morning is ideal because it reduces water lost to wind and evaporation compared to mid-day watering.
Mulching
Mulching is a protective layer for the soil during August planting. A three-to-four-inch layer of organic mulch, such as shredded leaves or straw, helps regulate soil temperature. This prevents the sun from baking the surface and reduces water evaporation.
Soil Preparation
The heat requires careful soil preparation to support new crops through establishment. Incorporating high-quality compost and organic matter into planting beds improves the soil’s structure. This is essential for both drainage and moisture retention. This amendment also provides a slow release of nutrients to support young plants. For new transplants, using a balanced, slow-release fertilizer can help them establish themselves quickly.