When reading about growing plants, reference is often made to something called pH. There are now pH meters available at garden stores that you can use to determine soil pH. With such emphasis, it all must be important, but what is pH?
Soil is made up of particles (sand, silt, clay) that vary tremendously in size. The surface of these particles holds and releases electrically charged portions of chemical compounds. For instance, water is composed of hydrogen ions, which are positively charged, and hydroxyl ions, which are negatively charged. When there are more hydrogen ions in the soil, it is acid; when there are more hydroxyl ions in the soil, it is alkaline; and when there are equal numbers of hydrogen and hydroxyl ions, the soil is neutral. The pH is the expression of this relationship. In an acid soil, the pH is less than 7; in an alkaline soil, the pH is more than 7; and in a neutral soil, the pH is 7. With time, soils tend to become acid, but there are some alkaline and some neutral soils.
To find the pH of your lawn soil, it is best to send a soil sample to a soil testing laboratory (most state universities have one). They not only can determine soil pH but also the physical and chemical properties and will provide recommendations on what needs to be added for a better lawn.
Ground limestone makes soil less acid. Use of lime can be overdone; so no more than 50 pounds per 1,000 square feet should be added at one time. This changes the pH slowly. Winter is a good time to apply ground limestone.
When a soil is too alkaline, flowers of sulfur or powered sulfur can be added either in granular form (mixed with sand or sawdust) or mixed as a suspension with water. This will make the soil more acid. Rely on soil test recommendations for the proper amount to apply.
The Lawn Institute, Box 108, County Line Road, Pleasant Hill, Tenn. 38578, recommends that a soil sample be tested for pH at least every three years and that recommendations for use of lime or sulfur to the soil be followed. This will help create the best possible environment for lawngrass plants. –
