If the grass is still growing, mow higher to encourage roots to go deeper, helps shade the roots, and slows down soil evaporation. It also helps trap any dew that may form during the night. Stretch the time between irrigations to the maximum. Water efficiently, wasting no water to runoff and water thoroughly. Don't water just a little bit; that only encourages weeds.
During severe water shortages, let the lawn go brown. A healthy lawn of a perennial grass, though completely brown, can survive months with no water and will recover quickly once rains return.
Once your geographic area is in the midst of a drought, it's too late to apply preventative measures (these will be discussed at the end of this article). It's now time to take damage control measures. Here are the tips:
If you're already in a restricted water use condition because of a drought:
Studies show that lawns on regularly scheduled fertilizer applications recover faster than those that are not regularly fertilized. However, don't apply fertilizer to your brown lawn in hopes of turning it green like your neighbor down the street that is secretly watering his lawn during the night.
Avoid excessive foot traffic on a stressed lawn.
As the lawn turns brown from an extended drought, weeds will continue to thrive as green patches. Now is a good time to apply spot applications of weed-killer to these areas. Avoid spraying it on the lawn as best you can, even for lawn-friendly weed-killers.
Don't water a little here and there or now and then it just makes the lawn worse. Lawns are designed by nature to shut down (go dormant) under extreme conditions. Putting a little water on the lawn fools it into thinking, "hey, maybe things aren't so bad" instead of preparing itself for a continued period of no water.
If you're allowed a little watering, concentrate on making certain your important trees and shrubs have an adequate water supply. These costly investments won't die right away from a drought and you may not see the damage for a year or so. Weakened woody plants are more susceptible to insect damage that may go unnoticed until it's too late.
Applying 1/20" of water daily supplies nearly 1" of water a week. Yet the lawn is not as healthy as if you had applied the water in one 1" or two 1/2" applications. The more water you apply at one time (provided it doesn't run off) the deeper and healthier the root system grows and the better that lawn is to extended water shortages.
Sandy soil is porous and water flows in and out of it quickly. To wet sandy soil to 6 - 8" depths, water in 1/2" increments
Loam is the ideal soil. It is porous, yet will retain moisture. Follow normal watering recommendations of 1" per week
Clay soil holds the most water, but it is slow to absorb and release it. Adjust your watering so that you stop when the soil begins to show run-off. Let the water soak in, then repeat until the required amount has been applied.
How grasses rank in need for water:
(Rated from needing to the most to needing the least)
- Perennial ryegrass
- Kentucky bluegrass
- St. Augustinegrass