Dethatching is the process of removing the layer of dead grass, roots, and other organic material (known as thatch) that builds up between the soil and the green vegetation in a lawn. Excessive thatch can prevent air, water, and nutrients from reaching the grass roots, leading to unhealthy turf. Dethatching is done using specialized tools called dethatchers or power rakes and is an important part of lawn maintenance to promote healthy, lush growth.