Your lawns ever increasing need for more water may be a sign of poor soil conditions. One way to use less water in maintaining lawn areas is by improving the water holding capacity of the soil.
The water holding capacity of soils is influenced by soil texture and the amount of organic matter present in the soil itself. Here in Colorado we primarily have sandy or heavy clay soils. Water will either drain through too fast or run right off the surface. Soils composed of small particles such as clay, have larger surface areas than soils with larger particles such as sand. Large surface area soils will hold more water. In sandy soils water will often drain away too quickly before plants can begin to use it. Clay soils can bind up water so tightly it is unrecoverable by the plant.
The addition of organic matter such as compost will improve the physical properties of the existing soil. Organic matter will greatly enhance the water and nutrient holding capacity of the soil. It will aid in water infiltration and drainage; enabling water to travel to the plants root zone where it can be utilized more efficiently. The amount of organic matter present in the soil will determine its water holding capacity. The best and easiest way to increase the amount of organic matter in the soil is by adding compost Just a 1% increase of compost in the soil can dramatically increase it’s ability to hold water.
Grass will need less water in April, a little more in May, and a little more in June, with the maximum needed in July and August, and adjusting back down again during the Fall months. By slowly ramping up the water used to the peak demand period and back down again we are better able to manage water use for each season.
Start with peak demand, usually during June and July of each year. This would be the time of year when temperatures are hottest and the grass needs the most water. Set the sprinkler clock to run for the maximum length of time needed or 100% in June and July. Temperatures fall a little in August, allowing run times to be set at 80 % of maximum. May and September are cooler yet, so run times could be set at 60% of maximum. Even less water is needed by the grass in October, set run times to 40% of maximum. The grass would need the least amount of supplemental water in April, allowing run times to be set at 20% of maximum.
This is intended only as a guideline. Each year is different. If we experience lower than normal amounts of rainfall, run times would need to be adjusted upwards. With greater than normal rainfall, times could be adjusted downward. To water your lawn more efficiently learn to use your sprinkler clock to adjust run times and frequency for the time of the year.