The Real North Texas Heat Problem: It Is More Than the Temperature
Suggested slug: /north-texas-summer-heat-gardening/
Meta description: Discover why North Texas summers damage plants and how nighttime heat, hot soil, wind, and reflected sunlight affect a garden.
A newcomer may look at a forecast of 100°F and think, “I have gardened through hot weather before.” North Texas heat, however, is not simply an afternoon temperature.
Plants face several forms of stress at once.
Hot nights prevent recovery
Plants lose water during the day. Under better conditions, cooler nights provide a recovery period. During a North Texas heat wave, nighttime temperatures may remain very warm.
The plant continues to respire while receiving little relief from heat stress. After several hot nights, even a well-watered plant may look tired, stop flowering, or shed leaves.
Tomatoes illustrate this problem. A healthy tomato plant may grow vigorously but fail to set fruit when daytime and nighttime temperatures remain too high.
Sunlight can be more intense than expected
A plant labeled “full sun” is not automatically suited to an exposed North Texas location.
Morning sun is different from western afternoon sun. A plant receiving six hours of morning light may perform well, while the same species beside a west-facing brick wall may scorch.
Brick, concrete, stone, fences, and light-colored walls can reflect or store heat. The air temperature near these surfaces can be considerably harsher than the official temperature measured at a weather station.
Hot soil damages roots
Bare soil and dark containers absorb heat. Roots need oxygen and function poorly when the root zone becomes excessively hot.
Mulch helps moderate soil temperature and slows moisture loss. Apply approximately two to three inches of organic mulch while keeping it away from trunks and plant crowns.
Container plants require special protection because sunlight can heat the entire root ball. Moving the pot a few feet into afternoon shade can make a significant difference.
Wind increases water loss
Hot southern winds pull moisture from foliage and soil. A plant may wilt even though it was watered that morning, particularly if it was recently planted or has a small root system.
Wind protection can include:
- Fences that filter rather than completely block wind
- Taller, heat-tolerant plants
- Shade cloth
- Grouped containers
- Temporary screens around new transplants
How to help plants survive
Water deeply enough to moisten the root zone instead of repeatedly wetting only the surface. Check the soil before watering again; saturated soil can suffocate roots and cause symptoms that resemble drought stress.
Other useful practices include:
- Water early in the morning.
- Mulch exposed soil.
- Provide afternoon shade to vulnerable plants.
- Avoid heavy pruning during extreme heat.
- Delay transplanting when a major heat wave is forecast.
- Do not force stressed plants with excessive fertilizer.
- Inspect irrigation regularly for clogged emitters or broken lines.
Most importantly, establish trees, shrubs, and perennials during fall or early spring whenever possible. Plants with established roots are far more capable of surviving July and August.
Suggested featured image: A North Texas garden receiving morning sun with shade cloth protecting plants from western afternoon heat.
Related reading: Drip Irrigation for North Texas Gardens and Growing Plants in Pots Through a Texas Summer.