We Love Stressed Lawns (To a Point)

Tips for watering a Bratty Lawn

It seems that the weather in Texas is feast or famine (though I think all states probably say that), and our irrigation and drainage team here in Dallas/Fort Worth went from numerous calls from clients needing drainage solutions to even more numerous calls for irrigation coverage solutions, all of this in in about a two week span. ? Lawns in Texas are quickly showing moisture stress, and this can be managed with some tips on watering and some key resources such as Texas A&M’s watermyyard.org??

Maintaining a healthy lawn during one of our legendary Texas summers can be challenging in any year, but especially difficult after the spring of 2024 where we had frequent, heavy rainfall, followed by high heat with no rain. The spring rains that made our lawns look so good may have spoiled our turfgrass roots like petulant children, and sprinkler scheduling is the key to keeping the grass green and the Homeowners Association out of your inbox.

Understanding Drought Resistance in Turfgrasses

Research consistently shows that certain watering strategies such as deep, infrequent watering can enhance the drought resistance of our warm season grasses (Bermuda, Zoysia, or St. Augustine lawns).? In very basic terms, plants respond to stress, and the right amount of moisture stress will trigger the development of deeper, more extensive root systems.??

Conversely, shallow, frequent watering can result in shallow, less developed root systems.? Given the frequency and intensity of our 2024 Texas spring, it stands to reason that the lawns in DFW may show signs of stress amazingly fast this summer.? Here’s how we can minimize the damage and keep our lawn happy and healthy

The Benefits of Deep and Infrequent Watering

One of the key findings from multiple studies (these are listed below) is that deep and infrequent watering encourages the development of deeper and more extensive root systems. The benefits are many but among the most notable are:

1. Deep and infrequent watering can create deeper root systems: As we move down into the soil profile, we’ll often see plenty of moisture below the 4-6 inch depth where most turfgrass roots reside.? The deeper the root, the better access it has to available water.
2. Deep and infrequent watering helps discourage disease: Many of the most common fungal pathogens of our warm season grasses thrive on moisture, particularly moisture on the leaf blade of the grass.? Allowing the top of the soil and grass canopy to stay drier simply creates conditions that these pathogens do not favor.
3. Deep and Infrequent watering can allow for better aeration and oxygen availability: Plants get their oxygen from the air in the spaces between the soil particles.? When these spaces (called macropores and micropores) are completely full of water, there is often insufficient air to keep the plant healthy.? Deeper watering with less frequency can allow for more air space in the soil, which in turn facilitates respiration, and we all like to breathe once in a while.

Practical Watering Tips for Homeowners

To implement these findings and optimize your lawn's drought resistance, consider the following watering practices:

1. Water Deeply but Infrequently: Instead of watering your lawn daily, aim for deep watering sessions once or twice a week. This encourages roots to grow deeper into the soil, making your grass more resilient to dry conditions.? Many clay loam soil types will only allow about 1/10th inch of water per hour to infiltrate (this is very slow) and may require short, repeated cycles during a watering event to best achieve deep watering.?
2. Monitor Soil Moisture: Use a soil moisture meter to check the moisture levels in your lawn. Water when the soil is dry to a depth of about 4-6 inches. This ensures that the water reaches the root zone where it is needed most.? Soil moisture meters can be expensive or cheap, we’ve found that a cheap meter is better than no meter at all.
3. Water Early in the Day: Water your lawn in the early morning when temperatures are cooler and winds are calmer. This reduces evaporation and ensures more water penetrates the soil. Many cities do not allow watering before 6pm or after 10am, following these general guidelines is not only being a good neighbor, it is the best way to make the most efficient use of your water dollar without encouraging disease.
4. Adjust Watering Based on Weather: Be mindful of recent rainfall and adjust your watering schedule accordingly. Over-watering can be just as detrimental as under-watering,and can be an expensive mistake.? Wear and tear on the system, cost of water, and plant replacements are often an avoidable expense when user friendly resources such as smart controllers and resources like watermyyard.org are utilized.
5. Consider Soil Health: Healthy soil enhances water retention and root growth. Products that add humates (we offer a service called Liquid Air) can improve the soil's ability to absorb, store, and release water when used consistently over time.? Adding compost as a topdress or as a pre-planting amendment can help enormously, however this can be challenging on an established lawn.
6. Start slow and monitor frequently: Given that root systems may be underdeveloped, it may be necessary to water with slightly more frequency in July of 2024 than in previous years, at least at first.? It is important to remember that seeing some stress is not necessarily a crisis, it simply means that it’s time to water, and adjustments can be made.? These warm season turfgrass will go dormant long before they die, and having a couple of stressed out spots in late June is arguably preferable to an entire dead lawn in late August.

Some additional practical tips

The difficult part for most homeowners is first allowing the grass to stress a bit, and then knowing when enough stress is enough.? We’ve found that observing the color of the grass can be very helpful, as lawns under stress can take on a bluish tinge, the leaf blades may roll up and look thin, and footprints will be visible for a longer time than normal.? Any of these signal that it is time to water.??

We’ve also found that using a wifi based controller can make clock and scheduling adjustments very easy as the run times can be adjusted from your smartphone from nearly anywhere.? This kind of access to the sprinkler scheduling combined with resources such as watermyyard.org can be a powerful combination in getting the correct amount of water each week.

References:

1. Carrow, R. N. (1996). "Drought resistance aspects of turfgrasses in the southeast: Root-shoot responses." Crop Science, 36(2), 371-377.

2. Qian, Y. L., & Fry, J. D. (1997). "Water relations and drought tolerance of four turfgrasses." Journal of the American Society for Horticultural Science, 122(1), 129-133.

3. Huang, B., & Fu, J. (2001). "Growth and physiological responses of creeping bentgrass and bermudagrass to elevated root-zone CO2 at different soil water contents." Journal of Experimental Botany, 52(364), 1203-1209.

4. Carrow, R. N. (1995). "Drought resistance aspects of turfgrasses in the Southeast: Root-shoot responses." Agronomy Journal, 87(4), 727-732.

5. Richardson, M. D., & Karcher, D. E. (2004). "Water use efficiency and rooting characteristics of zoysiagrass and bermudagrass." Crop Science, 44(4), 1435-1440.