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Scorching temperatures, elevated humidity and variable rainfall during Louisiana summers create challenging conditions for maintaining healthy lawns. Even though our warm-season grasses like bermudagrass, centipedegrass, St. Augustinegrass and zoysia are well adapted to these conditions, they still require proper management to perform well through the summer months.
Unfortunately, many of the problems we encounter during the summer are not caused by the environment alone, but by well-intentioned management practices that end up making things worse. If your lawn struggles during the summer, there is a good chance one or more of the following mistakes is to blame.
This is by far the most common and most damaging summer lawn care mistake. Many people assume that because it’s hot, the lawn needs water every day. However, shallow watering encourages short, weak root systems and creates constantly wet conditions that favor disease development and weed seed germination.
A good guideline is to apply about 1 inch of water per week, including rainfall. For help calculating how much your irrigation system is putting out, see the LSU AgCenter’s publication Louisiana Home Lawn Series: Simple Home Irrigation Audit. This amount should ideally be applied in no more than two or three irrigation events per week, rather than with daily watering. The common term we use is “deep and infrequent” watering. Remember, our warm-season grasses are well equipped to go for a few days with no water, and most probably even do better staying on the dry side.
Watering should also be done in the early morning hours. Evening irrigation keeps leaves wet overnight, which significantly increases the risk of disease. If your lawn feels constantly damp or spongy; you’re always battling dollarweed, doveweed and sedges; or if you notice increased disease pressure, there’s a good chance you’re watering too often or too much.
Footprints that remain in the grass indicate drought stress and a need for irrigation. Areas where footprints do not remain, such as near the top of this photo, do not need irrigation. Photo by Eric DeBoer
Scalping the lawn during the summer is one of the fastest ways to weaken turfgrass, reduce its ability to tolerate heat and encourage weed growth.
Each turfgrass species has an optimal mowing height range, and maintaining that height is critical for a healthy, resilient lawn. When grass is cut too short, it loses valuable leaf area needed for photosynthesis, which reduces energy production and weakens the plant. The result is a thin, stressed lawn that is more prone to weeds, drought stress and decline during extreme heat.
Recommended mowing heights for common Louisiana lawn grasses are:
One of the most overlooked benefits of mowing at the proper height is that it actually makes lawn maintenance easier. Taller grass reduces how much leaf tissue is removed at each mowing, making it easier to stay within the “one-third rule” without having to mow constantly.
The one-third rule means you should never remove more than one-third of the leaf blade in a single mowing. When lawns are cut too low, they require more frequent mowing to avoid removing too much tissue at once. When maintained at a proper height, mowing frequency becomes more manageable, and the turf experiences less stress overall.
In addition, higher mowing heights provide several key benefits during summer:
Also, make sure mower blades are sharp. Dull blades tear the grass rather than cut it cleanly, which creates a ragged appearance and increases stress and disease susceptibility. If there is one cultural practice that consistently separates good lawns from poor ones in summer, it’s frequent and proper mowing.
Mowing St. Augustinegrass too low leads to a weak, brown lawn. Photo by Eric DeBoer
It’s easy to think that more fertilizer will lead to a greener, healthier lawn, but during the summer, that approach can often backfire, especially when it comes to nitrogen.
Nitrogen is the primary driver of turfgrass growth and color, but applying too much during the summer can create more problems than it solves. Excessive nitrogen leads to rapid, succulent leaf growth that the plant cannot sustain under elevated temperatures and environmental stress. This type of growth is more vulnerable to disease, increases the need to mow and contributes to thatch accumulation over time.
Overapplying nitrogen can also reduce stress tolerance. Turfgrass that is growing too aggressively often develops a shallower root system and is less capable of handling heat, drought and traffic. In other words, the lawn may look good briefly, but it becomes less stable and more prone to decline as summer conditions intensify.
From an environmental standpoint, excess nitrogen is also more likely to be lost from the system. During heavy rainfall or irrigation events, nitrogen can move off-site through runoff or leach below the rootzone, particularly in sandy soils or heavily irrigated areas. This not only reduces fertilizer efficiency but can also contribute to water quality issues.
These totals should be split across the growing season, with lighter applications during the peak of summer. For most homeowners, that means no more than about 0.25 to 0.5 pounds of nitrogen per 1,000 square feet per application during summer months, if needed at all. More nitrogen does not equal a better lawn in August. In many cases, it leads to more problems than benefits.
Summer lawn care in Louisiana is not about doing more, it’s about avoiding the things that cause unnecessary stress. Deep, infrequent watering; frequent mowing at the right height; and moderate fertilization go a long way toward keeping lawns healthy through the hottest part of the year.
