Encouraging grass thicken up and also makes it stronger and less susceptible to disease
Thatch is un-decomposed stems and roots that accumulate near the soil surface. If the spongy layer above the soil is more than ¾- to 1-inch thick when you compress it, it is time to have your lawn dethatched. The best time for thatch removal is when your lawn is thriving in the Spring or Autumn.
Thatch is a build-up of organic matter which can include, dead grass leaves, stems, and overcrowded grass roots and lateral weed growth. Thatch can stifle the growth and health of grass or turf. Removing the thatch helps the grass by encouraging it to thicken up and also makes it stronger and less susceptible to disease. Reducing thatch levels increases the levels of water, air and nutrients that can get through to the root zone of the grass plants. Significant thatch problems in lawns can cause diseases and can encourage moss to grow in the areas where grass has died.