In arid parts of the country or areas with water restrictions, drought tolerant grasses are recommended for their ability to withstand extended periods without water. Certain species of grass are better equipped to handle drought because of their native conditions and some grasses are improved cultivars, bred for their drought resistance. Drought resistant grasses are one part of a drought tolerant lawn, along with healthy soil and proper cultural practices.
Cool season drought tolerant grasses vary in their drought tolerance, some need supplemental watering while others can survive on occasional rain alone. Some grow in natural looking clumps and can be too bumpy to serve as a play area, so it is important to choose the right plant for the right purpose.
Tall fescue is an adaptable, bunch-type grass with a course texture. Each plant grows from a single seed so it needs to be seeded heavily. With regular mowing, tall fescue can provides a "carpet" affect of a traditional lawn. It prefers 3/4" of water per week preferably in one deep watering and is very traffic tolerant.
Sheep fescue is a bunch grass that grows in clumps. It provides more of a natural look and needs very little water. It only needs fertilizing every other year and requires infrequent mowing but the bumpy surface is not recommended for backyard activities.
Buffalograss is native to the midwest and gaining popularity for its thick, lush turf, infrequent mowing needs, and hardiness.
It only needs 1/4" of water per week in the summer, but can survive on less. Buffalo is very slow to start from seed so it must be purchased in plugs and planted about 5" apart. Buffalograss should be mowed high (5") or not at all and makes a bumpy surface so it would not be good for backyard activities.
Wheatgrass varieties are coarse looking, all purpose grasses that need very little water or fertilizer. They are easy to start from seed and great for low maintenance areas.
Breeding, plant health, and cultural practices need to work together to provide drought resistance in a lawn. A water loving grass like Kentucky bluegrass can survive on half of its normal water requirement, if the soil is fertile, it's not mowed too short, and it's in good health. Likewise, fine fescues and ryegrass blends can become quite drought tolerant with proper management.
During extreme drought, some grasses will turn yellow and go dormant in order to survive without water. Dormant grass is vulnerable to traffic but it is not dead and will come back once it rains.
Unlike their cool season counterparts, warm season grasses love the heat. Their peak growing time is mid-summer when the temperatures are the hottest. Drought tolerant warm season grasses have the ability to survive on little water during these peak growing times. Many, but not all, varieties of warm season species are considered drought tolerant. Certain cultivars have been bred specifically for their drought resistance while others may be bred for their color, disease resistance, or geographic location.
Before choosing a warm season turf for a drought tolerant lawn, ensure that its cultivar is indeed drought resistant and suitable for your area.
Bermuda grass loves full sun and has excellent traffic tolerance. It responds quickly to watering after drought and requires frequent mowing. Bermuda grass tends to go dormant during the winter and is often overseeded with ryegrass in the winter to maintain green color. Common Bermuda, Celebration, GN1, Grimes EXP, TexTurf, TifSport, and Tifway 419 are all considered drought tolerant cultivars.
St. Augustine grass is a medium green, coarse leaf grass that prefers dappled shade and is acceptable for moderate traffic. It remains green for the winter months of dormancy but is susceptible to diseases if excessively watered during the winter. Floratam is considered the best drought resistant cultivar.
Zoysia grass tolerates sun and shade but is slow growing compared to Bermuda and St. Augustine. Once Zoysia is established, it provides a lush, green carpet of turf. Zoysia tolerates foot traffic well and different cultivars have varying tolerance to drought. El Toro, Empire, Jamur, and Palisdaes are considered drought resistant cultivars of Zoysia grass.
Buffalo grass is native to the midwest, requires full sun and does not tolerate much traffic. It requires little, if any, water once it is established. It needs to be established from plugs and must be mowed high (over 5" or not at all). All varieties of Buffalo grass are considered drought tolerant but some newer cultivars like Legacy are favored over others.
Centipede grass is "apple-green" or "lime-green" in color and although slow growing, makes an attractive, low maintenance lawn once established. It prefers full sun or partial shade and tolerates acidic soil so it is commonly found growing in the dappled shade under pine trees.
Bahia grass is a good all purpose grass with excellent wear tolerance, disease and insect resistance and it grows well in infertile soils. It is considered drought tolerant because of its prolific rooting but can thin out over time and is not suitable for shady areas.
As with any plant, drought tolerance can be increased by providing ideal growing conditions and cultural practices. Deep infrequent watering, healthy soil, and mowing at a species appropriate height can increase the drought tolerance of any plant, including lawn grass.