Scarifying a lawn will remove any thatch or moss which has built up. It can be quite a harsh process on a lawn, and the grass will need time to recover afterwards. It can also be a labour-intensive process if you’re using a hand rake. There are a few alternatives.
Power scarifier
For large lawns, if the thatch layer is very thick you might need to use some form of power dethatching equipment. These are often called vertical slicers, vertical mowers, verticutters, power rakes or power rakers. These machines are expensive, so most people choose to rent them rather than buy them. They will perform a fairly intense scarification.
Most power scarifiers have flail blades which rotate. Others have knife-like blades, which are fixed in place. They can be heavy and noisy, but will cover large areas easily and relatively quickly. You’ll need to be careful with the setting of power dethatchers – different types of grass need to have different settings.
Dethatcher attachments for lawn mowers
Some lawn mowers have a special attachment that acts like a power scarifier to remove thatch and moss. These can put excessive strain on the mower, which could cause it to wear out quicker.
Towed scarifiers
If you have a tractor or ride-on lawn mower, you might be able to find a scarifying attachment for it. These can cover large areas easily and quickly.
Liquid dethatchers
Thatch can be treated with liquid lawn dethatcher which contains microbes that feed on thatch, or chemicals to encourage the microbes. This helps to keep the layer of thatch down naturally. Using these treatments is much less labour intensive than raking. However, it could take a while for the thatch to break down and it may require repeated applications to establish enough microbes to prevent thatch build-up.