Earlier I discussed about how to water lawns and the reasoning behind proper watering. I would like to expand on that discussion.
Kentucky bluegrass will use from one to one and one half inches of water per week. To this amount, we would need to add for evaporation due to heat or wind. We would also subtract from this for any rain. Therefore, in the spring, we would apply between one inch to one and a half inch of water per week and in the summer, we would add between one and one half and two inches per week. If we add more than this amount, the grass may not use it.
However, we may want to add more than this amount if we have a dry soil or a sandy soil that does not hold water. The type of sprinkler used depends on how long you need to water. The larger the area covered the longer you need to leave a sprinkler in one area. One way to determine this is to place a container in different areas of the lawn and time the sprinkler say for 15 minutes and this will how the amount of water and the coverage of the sprinkler. Each type of sprinkler has a different pattern and volume of water discharged. The next consideration depends on soil type and layout of the lawn. For example, clay soil holds more water than sandy soils. However, it takes water longer to penetrate clay than it does sand. In addition, does your lawn face south or north? These questions will determine how often you will have to water.
Generally, in the springtime, we only need to water once per week and gradually then as summer temperature's increase, we need to water two or three times per week. I usually wait until the lawn starts to look dry, or when you walk across it your footprints show for a period of time, then I water. When watering it may take 20 minutes to over an hour per setting to water the lawn so the soil is wet down to six to ten inches. You can check by using a sharp probe (such as an old screwdriver), if it is easy to push in then it is generally wet enough. Try not to water during the day if the temperature is above say 80 degrees. This is because a lot of water will be evaporating before it goes into the ground the evaporation could equal 50% or more, however on really hot days say above 95 degrees a short 10 minute watering around noon will cool the grass down and help it cope with the heat.
The best time to water is when it is cooler and less windy. The biggest problems I see are people who water every morning for ten minutes. This creates shallow root systems, and promotes diseases. The other problem that can happen with late night watering especially in the springtime is diseases. Whenever the water is on a leave for more than an hour or so then diseases can start reproducing. Therefore, if we water and then have dew we could encourage a disease problem.
Lucky for us we have low humidity and a lot less diseases than other parts of the country. This summer especially we need to conserve our water and look for ways to cut back the amount of grass we water.
