It’s February and I am writing about Lawns!
Even well-established tall fescue or bluegrass lawns must be watered regularly throughout the growing season to keep them green and growing. Buffalo grass is the most drought-tolerant grass and often survives summers without regular watering. Bermuda grass and zoysia grass without excessive thatch require less water during stressful summers than do cool-season species.
Avoid watering established tall fescue or bluegrass lawns prematurely in the spring. Generally, there is a good reservoir of soil moisture remaining after winter, and during cooler springtime weather, grass plants require less water. Unnecessary irrigation can contribute to a shallow root system as summer approaches.
The recommended approach for watering established lawns is to wait for signs of general drought stress, and then apply sufficient water to moisten the soil to the depth of the root system. Established turf grass indicates drought stress by turning a dull, blue-green color. Moisture-stressed grass also tends to “footprint,” meaning that grass that is pressed down when walked on doesn´t return to an upright position. During an abnormally wet spring, grass may need to be weaned of moisture dependency by watering in gradually decreasing amounts going into summer.
Turf grass roots grow deeper in spring and fall than in mid-summer. To accommodate the root system, apply enough water to moisten the soil to a depth of 6 to 8 inches. This should take 1 to 1½ inches of water, depending on the soil type. On level sites with good soils, this much water may be applied at one time, but not faster than it can be absorbed by the soil. Water that puddles on the lawn may absorb enough heat during hot days to scald the grass. On slopes, water may have to be applied in increments, letting it soak in between cycles.
The objective should be to moisten soil to a depth of 6 to 8 inches during a 24- hour period, then let the soil dry out before the next irrigation cycle.
Because the root systems of cool season turfgrasses recede during hot weather, it may be necessary to water tall fescue 3/4 inch twice a week during July and August. It shouldn´t be necessary, or desirable, to water established lawns every day. Watering too frequently can kill your lawn!
When using an automatic timer to activate an irrigation system, pause it when rainfall is adequate. This can be done manually or with an automatic rain sensor override. For more efficient watering use in-ground moisture sensors or manually turn on the system as needed rather than following a set schedule. A screwdriver can be used to determine how deeply water has penetrated the soil. Push the tool into the ground until you reach
dry soil. The tool will pass easily through moist soil but will stop when it comes in contact with dry ground. Remove the tool from the soil and measure to determine depth of watering.
As homeowners become more sophisticated in their approach to lawn care, they should become more knowledgeable about the rooting depth of the grass on the site, the infiltration rate of water into the lawn, and how grass performs under stress. They should learn where grass tends to exhibit drought stress first, and use these places as a guide.
Water moves more readily into moist soil. To maximize the benefit of light rainfall, apply 1/4 to ½ inch additional water immediately after a rain. An established tall fescue or Kentucky bluegrass lawn has the capacity to enter a dormant condition when subjected to drought stress.
An established lawn consists of mature grass that has gone through a complete growing season. It is growing in good soil, maintained properly, and gradually eased into summer by weaning from moisture dependency. While dormant, lawns may go two to three weeks or more without water. After that, it´s important to keep the crowns of dormant grass plants alive by applying about ¼ inch of water every couple of weeks if that much rainfall doesn´t occur. By following this approach, established bluegrass and fescue lawns, growing on good soil and maintained appropriately, can survive up to 8 weeks without substantial irrigation.
During a dry winter it may be necessary to apply water during mid-winter thaws.