A healthy green lawn not only adds value to your home, but also creates beauty in your garden. However, if your soil contains too much clay, growing grass will be almost impossible. This is because the clay particles in the soil stick together, which prevents it from draining. Water will also run off the soil, taking valuable nutrients with it. You can amend the clay soil so that grass will grow and, although this will take a little patience and work, it will be worth the effort.
Check your soil to see if whether it contains clay and, if so, how much. Place a small amount of soil -- about 125 ml (1/2 cup) -- in the palm of your hand. Wet the soil slightly with a spray bottle to get it moist enough that when squeezed, it forms a sticky ball. Examine the soil to see if the ball remains tightly compressed, which means a high clay content, or if it separates because of a lower clay content.
Buy a test kit for soil from a nursery or garden centre, making sure the kit will test for pH, nitrogen and phosphorus. Use the test kit according to the directions to determine what you need to do to amend the soil. Add in an organic compost material such as bark, manure or mulch. Till or plough the compost into the soil so it will break up the clay and prevent it from sticking together. Add a lime mixture if your soil is on the acidic side.
Add nutrients to the soil by growing a cover crop of plants such as wheat or clover, which will bring in nitrogen. Grow the cover crop for a couple of seasons and then allow it to die off. Till or plough the plot of land to fully incorporate the cover crop and to grade the plot so it slopes away from the house or any other buildings to prevent flooding.
Disperse grass seed with a machine for larger plots or by hand for small areas. Water the newly seeded lawn thoroughly so the water soaks in at least several centimetres. Keep the soil moist until the seed germinates, then reduce watering to several times a week, unless the weather is very hot, then water more frequently until the grass is established.
Do not add sand to a high clay content soil as the sand will stick to the clay and make the soil even more compacted.