Tips for Keeping Your Lawn Alive in an Age of Water Rationing
Maybe the time has come to give up lawns altogether, but it you're not ready yet, here's how to squeak by on as little water as possible .
Lawn watering is growing controversial, especially in areas experiencing drought. It might just be time to give up the love affair with grass, at least grass one has to mow. In extreme dry spells, some lawns do go dormant—but how dormant and for how long depends on grass genetics and health. A Buffalograss species is shown below.
Drought Tolerant Grasses
Texas A & M University Extension Service, no stranger to drought, says about grass varieties, “Buffalograss, Bermudagrass and some of the zoysia varieties will probably survive without irrigation. They will become dormant until the drought ends, at which time they should green up again. Grass varieties such as St. Augustinegrass, centipedegrass, tall fescue, and some other species may be severely damaged or die during extended periods of drought. You may have to replant dead areas after the drought ends.”
Arizona has an eradication program for some non-native grasses, such as Buffelgrass. Buffelgrass is an invasive. Buffalograss is much prized, native, drought tolerant and really was buffalo food. University of Arizona Extension Educator/Agent, Rob Call, writes that the difference between the two grasses is like the difference between night and day. “Buffelgrass is an invasive species to be eradicated at all costs, while Buffalograss is a native grass much prized as a drought-resistant turfgrass. Buffalograss is so-called because it was the principal food for the huge herds of bison (“buffalo”) that once roamed the Great Plains.”
Are Lawns Worth Saving?
The Lawn Institute, a turf industry-backed organization, suggests that grass is good, and worth keeping around. They make some good points. Lawns do produce oxygen, sequester carbon and generally keep temperatures in suburbs and urban areas coolers. Of course, trees and other plants provide the same benefits, but grass is not "evil," per se. A better case may be made against grass when you look at how it's typically managed. Regular mowing reauires polluting equipment, and a lawn, unlike perennial plants or fruit trees, creates no food. So unless you're letting it grow wild, or using it for grazing a goat or some sheep, most lawns are really just ornaments on your property that don't pull their own weight.
Miserly Maintenance Tips
Nonetheless, let's assume you're not ready to convert your lawn to a permaculture oasis: Here are the Lawn Institute's best practices for shrinking water use:
- Water Early. The best times to water are early morning or twilight when there is generally less wind and heat. Using an landscape irrigation system set for early morning watering is most often used in desert areas for two reasons, first, because mornings are cooler, and second, cooler mornings mean less evaporation.
- Just Enough. Over-watering is much worse than under-watering.
- Water only when the soil is dry 4 to 6 inches below the surface. Most turfgrass plants can stay in a dormant state for at least 3-4 weeks without the grass dying (longer if the dormancy is induced by cold). If drought goes beyond the 4 week mark, apply enough water to rehydrate the grass slightly and wet the soil down to a 5-inch (12.5 cm) depth. A quarter-inch (0.6 mm) of water every four to six weeks will keep the vital turfgrass crowns hydrated and capable of greening up when temperatures cool and moisture is again available. In most cases, this will not green up the turfgrass, but it will keep the turfgrass plant alive.
- Do the "Spring Back" Test. Use a screwdriver or other probe to determine dryness. If grass doesn't spring back after being walked upon it might be time to consider a small amount of irrigation as previously suggested.
- Walk Elsewhere. Eliminate all traffic on the lawn especially during the heat of the day when foot traffic and even mowing can injure the turfgrass plants and cause almost immediate dehydration. Restrict watering to those areas determined as most important. Increase watering on areas near buildings and other heat reflecting surfaces and on high or sloped areas where wind can dry the lawn faster and water may not penetrate as deeply.
- Change Sprinkler Heads. Save water by installing specialized sprinkler heads to more precisely deliver the water, adjusting irrigation timers for seasonal weather conditions or by using computer-controlled irrigation systems with rain/moisture sensors that automatically respond to daily changes in weather conditions. If rain is expected turn off your sprinklers.
- Mow High. Follow the one-third rule when mowing, removing no more than one-third of the turfgrass leaf blade.
- Mow Early. Mow less and only in the early morning or evening when temperatures are cooler because turfgrass loses moisture after every mowing.
- Sharpen Up. Keep the mower blade sharp. Dull mower blades tear and shred the leaf blades of turfgrass rather than cutting them cleanly. Shredded leaf blades increase water losses. Drought stress will occur faster on lawns with poor soil conditions underneath
- Observe Soils. Soil compaction, clay fill, high pH, and general poor conditions for root growth become evident under stress conditions such as drought. Although immediate corrections may not be possible, make notes of problem areas that will need to be addressed later.
- Trust in Providence. At the end of a drought, when cooler weather returns, or when watering restrictions are reduced or eliminated, grass will naturally begin to recover.
For more information about lawns and lawn care maintenance click on The Lawn Institute.