Scarify for the first time now in March, again in the middle/at the end of May and a third time at the start of September. Each time you scarify, as with mowing, change the direction from which you approach the stem and work diagonally now and again - as explained in the information on the best cutting technique above. After scarifying, add lime and fertiliser and re-sow gaps if necessary. It is best to carry out aerification after scarifying.The soil of a lawn is often not sandy enough for the roots to get enough air resulting in stunted growth. With the help of a simple digging fork you can stamp holes into the lawn and fill them with coarse sand. This allows water from the surface to flow away and also provides the roots with oxygen. In order to clear away dead roots and other debris you might want to scarify your lawn. By removing the lawn thatch you provide more breathing space for the lower parts of the grass and help the stems grow better.