Serious water shortages are a common occurrence in many parts of North America and improperly growing and maintaining a home lawn can be a huge burden on the water supply.
In many cases, lawns are being scapegoated as water-hogging sponges that do nothing but pollute the environment and waste valuable water resources. While this may be true in some cases, your lawn does not have to be that way. A properly managed lawn, made up of the appropriate grass species and balanced soil, can be functional and use little or no supplemental water.
Proper soil management is key for any lawn, including a lawn experiencing drought conditions. Healthy soil allows maximum opportunity for root systems to develop and grow. A deep extensive root system is what the grass plant draws its energy from in times of stress (drought). Compaction, thatch, poor pH, and soil composition can all have a negative effect on soil health. Through cultural practices like top-dressing, aerating, de-thatching, composting, and liming, soil can be amended to provide ideal turf-growing conditions.
The composition of the soil will also determine its water-holding capacity and ability to retain and transfer nutrients to the plant roots. Sandy soil has less nutrient and water retaining ability than loamy soil, therefore, turf is weaker and root systems are more vulnerable to drying out in a drought-stricken sandy soil. Humus-rich compost can be added to the soil profile through repeated top-dressings or renovation, aiding in water and nutrient retention.
One of the main reasons lawns are targeted as the number one villain in a drought is due to the untold amounts of water that is wasted while attempting to keep it green. Managing water consumption can radically reduce the amount of water needed to grow and maintain a lawn and allow it to survive under drought conditions.
Conventional sprinklers can be very wasteful and limiting if left unattended or used to water hard-to-reach areas. An automatic irrigation system can maximize the efficiency of watering by irrigating only the turf and not the sidewalk, driveway, or road. Timers can dial in the needs of any particular climate, grass species, or soil type, allowing for accurate watering down to the minute.
It is a good idea to have older irrigation systems audited by a professional irrigation company. The company can ensure devices like backflow prevention valves are in place and check for leaks, drips, and other inefficiencies.
When watering the lawn, it is best to mimic nature and irrigate deeply and infrequently to simulate natural rainfall. This will also encourage deep rooting by forcing the roots to search for water. Lightly watered turf creates shallow-rooted plants which need water all the time and are ill prepared for a drought.
Drought Tolerant Grasses
Drought-tolerant grasses are grasses that require less water than traditional turf species and are capable of withstanding extended periods without water. In most cases, drought-tolerant characteristics have been enhanced through selective breeding resulting in new and improved cultivated varieties. Drought-tolerant species include not only fescues and buffalograss but improved varieties of fine fescues and bluegrass. A balanced soil plays a large role in the ability for grass to withstand extremes, so again, have the soil tested and go from there.
Typically a lawn would require about 1 inch of water per week, applied in one or two deep waterings. Drought tolerant grasses require anywhere from 3/4-inch to 1/4-inch of water per week. These are optimum growing conditions though and a healthy, drought tolerant lawn, grown in ideal soil conditions, will undoubtedly be able to withstand extended periods without water. In extreme drought, where no supplemental water is available, many kinds of grass "brown out" and go dormant in a last-ditch effort to not die. Dormant grass is not dead and it will come back when it rains.
A lawn going through a drought is stressed. Drought is one of those times when it is best to just not do anything to your lawn. Mow as little as possible. Mow the grass high, 3 to 4 inches, or the highest setting on the mower. The added leaf blade tissue aids in storing water and photosynthesis. Do not fertilize, do not aerate, do not de-thatch, and do not top-dress. Do not do anything to bring added stress to the plant, including aggressive lawn activities and foot traffic.
Sometimes, it may be more prudent to not grow a lawn in a severely drought-stricken area. There are many attractive ground covers that have the same effect as lawn and provide interesting texture or foliage, yet require little or no supplemental irrigation. Xeriscaping is a method of landscaping using plants that require little or no water, which may be appealing instead of grass.