As time goes by, the dirt in your lawn becomes more compressed. Mainly, this occurs due to foot traffic or rolling large machines, such as lawn mowers over it throughout the seasons. Your lawn may also become compacted if it has a heavy composition of clay which is a very dense material.

Generally, plants and grass do not do well in compacted soil. The roots of plants require oxygen to help them grow, but compacted soil is so dense that it has much of the air squeezed out of it. Added to that, many beneficial insects are turned away from soil that has become so dense that they find it difficult to bore through it. In frustration, they seek a more hospitable terrain, possibly in your neighbor's lawn. Over the years as the grass roots get less and less oxygen and nutrients delivered to them because of the impacted soil, your grass slowly begins to suffocate and starve.

So how dense is your soil? A simple way to determine is to take a screwdriver and try pushing it into the dirt. You should do this when the ground is dry. If you get a lot of resistance, then it is probably a sign be a sign that your soil is too densely packed. If the dirt gives way without too much effort, then it's probably ok.

One of the main factors contributing to dense soil is not enough of humus in the soil. Humus is the material that is left behind after microbes have finished digesting organic matter such as lawn clippings, decaying plants, food garbage, and so on. When the microbes have completed their work, what is left is a dark moist substance that is incredibly rich in nutrients and trace minerals called humus.

Humus is a bona fide "super food" and by occasionally spreading it on your lawn's surface or mixing it with your lawn's top soil, you can invigorate your entire lawn. Humus regenerates your soil by restoring lost nutrients to it. It is a very spongy material and, particularly if your soil has a high percentage of clay, it will make your soil less dense. And unlike many chemical fertilizers, humus will not burn your lawn or other garden plants and it's very difficult to give your lawn too much of it.

If you have the room in your back yard, you can choose to produce your own humus. It takes time, but with the right equipment, it's not difficult at all. Otherwise, there are many organic garden centers where you can find organic, fully decomposed humus

Soil rich in humus also has another great benefit. It helps to keep your grass roots moist by preventing water evaporating from the lawn. This not only means that you need to water less, but also your lawn will be less susceptible to periods of rain draught. This is especially true if you have a sandy type of soil which tends to have difficulty retaining water.

Many gardeners believe that the high concentration of nutrients in humus that it passes onto the grass, helps the grass to fight off disease and bacteria.

Just like the human body, the health of your lawn is very much dependent on what you feed it. If you feed it junk food, which is what many chemicals are, your grass will grown but it will not be strong. If you feed it humus which is the equivalent of giving it vitamins, minerals and proteins - your lawn will grow to be strong and healthy.