Doing an inexpensive soil test will help you greatly if you want a thick, healthy lawn.
Home soil sample kits can be purchased at most home improvement stores and a variety of online retailers. If you only need to test your lawn soil look for the soil kit designed just for that purpose.
While wearing rubber gloves collect a small handful of soil from at least six different locations around your yard. When collecting the soil only gather it from the top three inches so to get soil that your grass actually grows in. This will give you the most true soil reading. Don’t use your bare hands because even small amounts of sweat can throw off a reading. Remove any grass or rocks and mix the soil into a good blended sample. Most home tests will ask you to mix the soil with water well then allow the soil to sink to the bottom before you use the test. Make sure to follow you chosen test exactly for best results.
Your test results will give you the pH level of the soil. It will also tell whether you have too much or not enough amounts of potassium, phosphorus and nitrogen. Once you know these you can add soil amendments where necessary to get the soil where it needs to be. This can be done by applying chemical fertilizer or through organic means.
If you get your lawn back in balance you will be surprised at how much easier it is to keep looking beautiful and green.