Preparing Your Lawn for Drought
In Oklahoma, drought is a frequent challenge, especially during the hot summer months. Preparation is essential for enhancing the resilience of lawns against dry periods. Being prepared by implementing the right practices early on allows homeowners to improve the resilience of their lawns during the drought conditions. A lawn that is well-prepared stands a better chance of surviving drought and requires less water overall, leading to more sustainable management.
Water Wisely
Oklahoma’s climate is marked by variable precipitation patterns, typically with heavy spring rains followed by summer droughts. To prepare your lawn for summer drought, once the rains subside, monitor your lawn for signs of drought stress— such as wilting (Fig 1), a bluish color changes or visible footprints—before applying supplemental irrigation. This encourages roots to grow deeper in search of moisture, which is especially important after a wet spring of continuous rainfall. Avoid light, frequent watering unless addressing newly seeded areas, as this can promote shallow root growth and increase the risk of weed infestation in established lawns. If your lawn has been watered frequently and shallowly, transition gradually to deeper watering practices.
For each irrigation event, apply enough water to thoroughly wet the root zone. If you notice water puddling or running off (Fig 2), turn off the system and allow it to soak into the soil. Grasses in coarse, sandy soils will need more frequent watering, but in smaller amounts compared to those in fine-textured clay soils, as sand holds less water than silts, loams and clays. Increased irrigation frequency and total water amounts are also necessary during hot, dry, windy or sunny conditions. Regularly check soil moisture with a trowel or soil probe and ensure the total weekly precipitation, plus irrigation, does not exceed the water requirements of the specific species. Historic evapotranspiration data can be found in the fact sheet (Id: L-434). Early morning watering is preferred to maximize efficiency, reducing wind drift and evaporation losses. For more irrigation tips, refer to fact sheet ID: L-434.
Raise Mowing Height
Maintain a higher mowing height throughout the growing season—ideally 2 to 3 inches for warm-season grasses and 3 to 4 inches for cool-season grasses (see fact sheets Id: L-441 and L-442 for more details). When mowing, remove no more than one-third of the leaf blade at a time. Taller grass provides shade to the soil, helping conserve moisture and improving photosynthesis through increased leaf area. This enhanced photosynthesis supports deeper root development, which helps the turfgrass better withstand dry conditions.
Optimize Fertilization Practices and Avoid Excess Nitrogen Fertilizer
Conduct a soil test to assess nutrient levels and adjust soil pH before drought conditions set in. Based on the test results, apply phosphorus (P) and potassium (K) as needed. Avoid excessive use of quick-release nitrogen fertilizers—limit to no more than 1 pound of actual nitrogen per 1,000 square feet before and during hot, dry periods. Too much nitrogen can encourage excessive shoot growth at the expense of root, rhizome, tiller and stolon development. This imbalance increases water demand for shoot growth while compromising the roots. Excess nitrogen can also lead to thatch buildup. For bermudagrass fertilization guidelines, refer to fact sheet ID L-441, and for cool-season turfgrass, refer to fact sheet ID L-442.
Use Herbicides Properly
When applying herbicides, using the lower end of label-recommended rates is generally less stressful on plants compared to maximum label rates, and overuse should always be avoided. Most if not all pre-emergent herbicides commonly used by consumers in turfgrass lawns can inhibit cell division and restrict root development (Fig 3). During the re-establishment phase following stand loss caused by winter kill, pest damage or drought, or during the grow-in process, it is important to focus more on post-emergent weed control strategies to minimize stress on the recovering turf.
Improve Soil Compaction
To alleviate soil issues, use high-quality topsoil and implement effective strategies to manage compaction. Compacted soils restrict root growth, making plants more vulnerable to drought stress. A common solution is core cultivation or aerification, which helps break up compacted layers and allows roots to grow better and access deeper moisture reserves. Aerification is also beneficial in high clay conditions or areas with excessive thatch. It is recommended to leave the soil cores on the lawn, breaking them up and dragging them back into the surface. For even better results, consider topdressing with organic materials like compost, which can boost soil health and add essential organic matter. Core cultivation is most effective during periods of active turf growth—late spring or early summer for warm-season grasses and early to mid-autumn for cool-season grasses. This is particularly important in new builds where construction equipment often compacts the soil, creating physical barriers that restrict root growth.
Other Thoughts
In Oklahoma, fall drought can also pose a significant challenge alongside summer drought. Proper lawn management during the fall is crucial to preventing winterkill. A common misconception is that fully dormant grass requires no care; however, even dormant grasses need adequate soil moisture. Occasional light irrigation during extended dry periods in winter helps keep grass hydrated, reduces the risk of winter desiccation, and enhances survival through the colder months.
Conclusions
In summary, implementing proper lawn care practices such as deep, infrequent watering, proper mowing techniques, strategic fertilization and addressing soil compaction can significantly improve your lawn’s ability to withstand drought. These proactive steps not only help your lawn endure summer stresses but also support its long-term health and resilience. Additionally, ensuring adequate moisture during fall and winter dry periods is crucial to preventing winter kill caused by extreme dryness (desiccation).
Figure 1. Turfgrass showing early signs of wilting on the left, characterized by folded leaves. On the right, turfgrass with fully expanded leaves, exhibiting no visible signs of drought stress.
Figure 2. Avoid water runoff caused by overwatering, as shown in the example above.
Figure 3. Root inhibition in bermudagrass following the application of pre-emergent herbicides. Note that the nodes on the stolons (runners) fail to develop roots, preventing them from establishing in the soil.
References:
Martin, D., D. Hillock, J. Moss, J. Shrefler, and E. Rebek. 2017. Bermudagrass Lawn Management Calendar. Id: L-441. https://ex-tension.okstate.edu/fact-sheets/bermudagrass-lawn-management-calendar.html
Martin, D. J. Moss, E. Rebek, and D. Hillock. 2017. Cool Season Lawn Management Calendar. Id: L-442. https://extension.okstate. edu/fact-sheets/cool-season-lawn-management-calendar.html
Moss, J. 2019. Irrigation. Id: L-434. https://extension.okstate.edu/fact-sheets/irrigation.html