Lawns are basically a mat of individual but intertwined grass plants. They are part of an ever changing ecosystem. To maintain the correct balance we must intervene at some point. Autumn is the best time for this. The three factors we have to work on are as follows:
The mix of plants is ever changing. Some grasses die through things like disease or drought. Others germinate from seed present in your soil originally or from seed blown or carried in from elsewhere. You want to shift this mix in your favour
As these life cycles of the plants progress it causes the build up of thatch, the fibrous layer between the grass plants and the soil below. The thatch also builds up through high usage of fertiliser, moss etc.
The third factor is that when you walk, play and use your lawn, you cause the soil to compact and seal over, preventing air from reaching the roots of your grass plants.
At the end of the summer period, after you have had the most use and enjoyment out of your lawn, you should consider an annual (or at least every 2 years) renovation.
It will repay you the following years many times over.
The procedure you should carry out is this:
Mow your lawn short, remember that this will be best done over a sequence of weeks, dropping the mower cutting height each week. The shorter your lawn before renovation the better, it makes your work much, much easier.
