Scarifying is a very beneficial lawn treatment and rather than being considered as a remedial maintenance exercise every one to two years, you should consider scarifying as a regular maintenance procedure.
What does scarifying do?
During the course of a season dead grass (called thatch) and lateral grass stems build up, thus restricting light and air getting through to the grass roots. As thatch builds it restricts any desired grasses and instead moss and weeds are encouraged to take over, leading to a downward spiral in the health of a lawn.
A scarifier is in effect a vertical mower with knife blades (or wire tines) spaced out along a reel – much like a cylinder on a mower. These vertical blades act like a vigorous comb, forcing out any build up of rubbish at grass root level. They can be lowered, or raised, to combat the depth of thatch, or in some applications, penetrate into any crusty soil layer.
The deeper the blades go, and the more extreme and vigorous the action is on the roots, potentially the more beneficial this remedial action has on grass roots.A deep incision into the soil cuts through any shallow grass roots, which in stimulates tillering – tillering occurs when the grass sends out new shoots where a root has been pruned.
Scarifying is effective if you want to remove a build up of dead grass or take out any unwanted lateral grass growth. It is especially beneficial if carried out during active growing season.
Regular root pruning will encourage a thicker grass root zone and aid crowding-out of undesirable weeds whilst also discouraging moss.
A scarifier can be set just to brush the soil surface without any interference with the roots of the grass.