Knowing exactly when to start particular garden tasks can be one of the most challenging parts of gardening. When should you sow a certain seed? What month of the year should a variety of plants be clipped back? There are thousands of questions, but the one I’d like to answer today is when to scarify your lawn.

Before we begin to answer that question you may be thinking ‘What is scarification?’. Scarification is the removal of thatch (the tightly webbed network of dead stems and roots of grass that form between the growing layer of grass and the ground). Thatch removal allows important nutrients to reach the roots. Leaving a lawn to accumulate too much thatch results in an unhealthy lawn that is spongy and full of moss.

There are various tools you can use to scarify a lawn. The simplest yet most labor-intensive tool is a garden rake. A rake is pulled through the grass and its metal tines pull up the thatch and pass the blades of grass mostly unharmed. The mechanical version of this is a scarifier, and instead of pulling tines through the grass, the tines are revolved on a tube (known as a cassette) mechanically. An example of a modern scarifier is our Sherpa Petrol Scarifier.

So, when to scarify your lawn? There are two times of the year when you can scarify your lawn, that is spring and autumn. The reason for this is that these two times of the year are the only periods that satisfy the following criteria:

  • The temperature is high enough that the grass is at a growing stage and may continue to grow after scarification 
  • The soil, grass and thatch aren’t too dry (such as in summer) as this will be a futile task

Spring (around April) and early autumn generally satisfy these times of the year. An informative article goes into further detail here.

Some people prefer Autumn over spring, as you can do more thorough scarification (as the bare grass will not be as unsightly over the winter compared to doing it in the spring). This is then an ideal time to overseed the ground, as it will be aerated from the scarification. By the time the grass grows back it will look much better than it did before.