Lawns are subject to a lot of criticism for their consumption of water, especially in arid climates where water is a limited resource, or during times of drought. But the truth is that most lawns are grossly overwatered and do not need nearly as much moisture as most homeowners give them.
Here are some tips for training your lawn to grow in arid conditions and to survive temporary droughts with a minimal use of water.
In this case, watering correctly means watering less. Weaning a lawn off of its water addiction is the first and most important step to a more water-efficient lawn. The common practice of automatically watering a lawn each morning is a very poor practice, as it essentially "trains" a lawn to need this gulp of water each day. Turfgrasses that get this kind of regular shallow watering tend to grow shallow roots that will die if their daily "fix" of water is denied. And with daily watering practice, a great deal of the water simply evaporates away—a complete waste of precious moisture.
Limiting the amount of watering will gradually train your lawn to send down deeper root systems that will be much more efficient at using whatever moisture is in the soil. Even water-loving grass species such as Kentucky bluegrass are capable of surviving and thriving with much less water than they are normally given.
When you do water in a dry climate or during periods of drought, make sure to do it when evaporation is minimized. Water in the morning before the presence of harsh sun that will evaporate away the moisture before it can soak into the soil. And avoid watering on windy days, where evaporation will also be accelerated.
One watering each week, done under the right conditions, is much more effective than daily shallow waterings.
Adapt to Summer Heat
Your lawn may be the center of family activity in the spring and fall (and in the winter in warmer climates), but the heat of summer requires a different approach, both in how you use your lawn, and how you care for it. Now is the time to reduce foot traffic on the lawn and to keep maintenance practices to a minimum. Aerating and dethatching should be done in cooler seasons, not in summer. Mowing grass to a taller height will shade the soil and keep roots cooler.
Reduce Stress During Drought
Beyond "training" a lawn to survive with less water, there are management techniques you can use to help the lawn during times of drought. Not surprisingly, staying off the lawn is the biggest help. While summer is a time to reduce foot traffic, drought conditions are a time to eliminate it altogether. Avoid any kind of major lawn care maintenance during drought periods, and take your pets to the dog park or on long walks rather than letting them play on the lawn. Mowing will already be less necessary as hot, dry weather sets in and slows the growth of the grass, but its best to avoid mowing altogether during drought periods unless it's absolutely necessary.
During drought, grasses can be allowed to go dormant, but unless there are local watering prohibitions, make sure to water just enough to keep the grassroots alive. According to turf scientists, turf grasses can go dormant for up to four weeks without permanent damage. If a drought goes beyond four weeks, water deeply enough to rehydrate the grass slightly and wet the soil to a depth of 5 inches. This will not necessarily cause the grass to green up, but it will keep the grassroots alive.
Plant Drought-Tolerant Grasses
In both cool-season and warm-season regions, there are grass varieties that have lower water needs. A lawn can at any time be replanted or resodded with a grass mix that has lower moisture needs, or it can be converted more gradually by annually top seeding with seeds of more suitable grass species.
Over several years, the more drought-hardy grasses will thrive as others gradually die away.
In cool-season regions, Kentucky bluegrass is the most prevalent lawn grass, but it also is very demanding in its need for water. Even in cool-season climates, water availability is becoming a more serious issue, and many homeowners are now replacing Kentucky bluegrass with fescues that require less water and are better able to withstand drought.
In warm-season regions, drought-tolerant grasses have been coming into popularity for some time, especially in the southwestern U.S. There are many choices for drought-tolerant grass species for warm-season climates. Some grass species have been selectively bred to offer drought-tolerant cultivars. Some thrive in year-round arid environments while others approach near-dormancy until the rainy season, when they jump back into periods of growth.
It's a universal rule of thumb that most lawns are mowed too short, but it is especially important to mow to a longer height in arid climates and in drought conditions. It is the grass blades (leaves) that store most of the plant's moisture, and longer grass means more moisture to supply the plant roots. Longer grass also provides shade to the soil, which keeps it cool and minimizes moisture evaporation.
Amend the Soil Where Necessary
This is difficult to do with an established lawn, but when seeding or sodding a new lawn, amending the underlying soil with plenty of organic material will help the soil retain moisture that can be utilized by the roots of the grass plants. Sandy soils drain so quickly that lawns have difficulty obtaining the moisture they need, while soils heavy in organic material can support lawns much more effectively.
On an established lawn, you can maintain and improve the amount of moisture-retaining organic material by mowing with a mulching mower that keeps grass clipping on the lawn, or by annually top-dressing the lawn with compost or another organic material.
Downsize the Lawn
Where water is a precious commodity, the best solution may be to reduce the square footage of yard space devoted to living grass. Adding decks, patios, courtyards and other surfaces will not only reduce the amount of water needed to support grass but will also reduce your lawn maintenance chores.
Many areas of the country have experienced major droughts and water shortages resulting in bans, restrictions, and a cultural shift towards water conservation. Where water is scarce and a large lawn is no longer practical, it makes sense to downsize. If a lawn is still desired for children or pets or even aesthetics, there's no need to eliminate it completely—just make the area smaller and easier to manage.
Convert to Alternative Groundcovers
Even drought-resistant grasses require more water than some other groundcover species. In regions where low-moisture conditions are permanent and inevitable, you might want to consider giving up grass altogether and converting yard space to another form of living groundcover. Some options include:
For shady areas:
- Periwinkle (Vinca minor), USDA hardiness zones 4 to 9
- Creeping mahonia/Oregon grape (Mahonia repens), USDA hardiness zones 5 through 9
- Sweet woodruff (Galium odoratum) USDA hardiness zones 4 through 8.
- Creeping thyme (Thymus serpyllum), USDA hardiness zones 3 through 9.
For sunny areas:
- Rockrose (Cistus spp.), USDA hardiness zones 8 through 11
- Snow in summer (Cerastium tomentosum), USDA hardiness zones 3 through 7
- Moss phlox (Phlox subulata), USDA hardiness zones 2 through 9
- Winecups (Callirhoe involucrata), USDA hardiness zones through 11
Consider Artificial Grass
Although it's not for everyone, a surprising number of homeowners, even in cool-season climates, are choosing to give up living grass and groundcovers in favor of lawns made from artificial turf. In desert environments, especially, water restrictions make living lawns quite impractical, and a little patch of artificial turf may be all that's needed for a pet or sitting area. Maintenance is easy and many varieties of artificial turf look and feel very much like the real thing.