Weed Control/Irrigation Equipment
Proper watering is essential to maintain a healthy lawn during dry periods, but overwatering can cause more damage than a lack of water. Potential consequences of overwatering include increased incidence of crabgrass, increased disease problems, shallow rooting, and higher than necessary water bills. When watering a lawn, it is better to err on the dry side rather to overwater.
The frequency of watering needed varies from site to site and should be determined by turf appearance. The first signs of water stress in a turfgrass are a bluish-green color and when footprints remain in the turf after walking across it. Turfgrasses can easily withstand this much water stress without a decline in turf quality, and there is no real benefit to watering a turfgrass stand before this point.
As water stress increases, the turf wilts and can have a grayish-green color. Turf that has wilted should be watered immediately. Wilted turf should recover quickly after watering. Severe drought stress will cause the leaves to turn brown and the grass can die. Watering at this point may help the turfgrass plants survive, but it will take about two weeks until the turf produces new leaves and signs of recovery can be seen.
The watering schedule for turfgrasses depends on a number of factors. Watering on a set schedule without considering the needs of the plants can result in overwatering. Automatic irrigation systems should be reset as needed to meet the needs of the turfgrass.
The
amount of water your lawn needs depends on weather, soil type, slope, etc. Water
should be applied in a single thorough soaking, or two equal applications of
water three to four days apart rather than in light irrigations every day. Daily,
light irrigations promote shallow rooting, non-drought hardy turf, and encourage
crabgrass. The soil should be wetted to the depth of the deepest turfgrass roots,
usually about 3".
Lawn
sprinklers should be left in one location for at least two to three hours to
thoroughly wet the turfgrass root zone. Automatic irrigation systems with spray
heads that distribute water in all directions simultaneously are capable of
applying a large volume of water in 10 to 15 minutes if water pressure is adequate.
Automatic irrigation systems with rotary sprinkler heads that have one stream
of water are capable of applying the necessary water in 30 to 40 minutes. Many
different types of underground sprinklers are available, some that pop up when
water pressure is applied and remain hidden below ground when not in use.
Place shallow, straight-sided containers in a grid pattern around the sprinkler to estimate the amount of water applied. Operate the sprinkler for a specified length of time and measure the depth of water collected in the cans. This can be used as a guide in determining the amount of water applied in that time period, and can help determine how long to let sprinklers should operate in one location.
If possible, lawns should be watered between 4:00 a.m. and 8:00 a.m. At this time, line water pressure is usually the highest, there is normally not much wind, and evaporation is low. If this is not convenient, the second best time to water is from 8:00 p.m. to 12:00 p.m. A potential problem with watering in the early evening hours is a greater incidence of disease. Disease problems can be reduced by watering only when the turf needs water and by watering infrequently but deeply.
While watering in midday does not cause the turf to burn, it is not as effective because of the water lost to evaporation.
Slopes or areas with soil compaction are difficult to irrigate without the water running off. Water should only be applied until it just begins to run off. After the applied water has infiltrated, the process can be repeated until run off occurs. Repeat this cycle several times until the soil is wet to a depth of six inches.
In extended droughts when a lawn is not watered, the turfgrasses will wilt and the leaves will turn brown. These lawns have become dormant. This is a survival mechanism of turfgrasses. The leaves may be dead but the crown (growing point) and the root system remain alive. Since turfgrasses lose water through the leaves, little water is lost from dormant plants. Turf can survive four to six weeks in a dormant condition without a significant thinning. During persistent dry weather, water dormant turf thoroughly every four to six weeks This will not cause the turf to green up but should provide enough moisture to keep the plant alive. As soon as regular rainfall or irrigation begin, the turf should develop new leaves and begin to grow actively.
A newly seeded lawn should be watered two to four times a day. The seed bed should be moistened to a depth of 1or so but not saturated. As the seeds germinate and begin to grow, they must not be allowed to dry out. When the seedlings reach two inches in height, begin to water less frequently and more deeply. After it has been mowed two or three times, waterings should be infrequent and deep.
A newly sodded lawn should be watered once or twice a day until the entire thickness of the sod is wet and the soil underneath is moist to a depth of one inch. DO NOT OVERWATER AND DO NOT SATURATE THE SOIL BELOW THE SOD. As sod becomes established and roots penetrate the soil, gradually reduce the frequency of watering. After it has been mowed three or four times, use deep, infrequent waterings.