Grass thatch can be a good for your yard, as long as the grass thatch is not excessive. Excessive grass thatch can cause problems for your yard, and should be periodically removed by a process called de-thatching.
Understanding grass thatch, and what it consists of is fairly simple. Grass thatch is a layer of dead and living weeds and grasses, including stolon, roots, and rhizome, that grow between your healthy grass and the soil in your yard. It is normal to have grass thatch, and most healthy lawns will have at least a thin layer.
A thin layer of grass thatch in your yard is not only common, but it can have its benefits, as well. A layer of grass thatch that is less than 1/2 inch in depth can aid in:
limiting weed growth
Protecting grass from early frost damage
Reducing water evaporation
When grass thatch becomes deeper than 1/2 inch, it can have the opposite effects. Some of the effects of excess grass thatch include the prevention of the proper flow of water, air, and nutrients to your lawn's root system and can also promote the growth of yard fungus.
Grass thatch should be removed using a process called de-thatching (De-thatching is commonly done best by a mechanical machine) once it becomes deeper than 1/2 of an inch.
To reduce the amount of grass thatch build up in your yard you can be sure to:
Rake all fallen leaves in the fall
Rake all excess grass clippings after mowing
Avoid over watering your lawn
Avoid over fertilization of your yard
The best time to have your lawn de-thatched is while the grass is still living and growing, to enable the grass to recover fast from the strenuous de-thatching process it endures. If de-thatching in the spring, it is best to do it in the late spring months, to give the grass time to begin to grow regularly. If de-thatching later in the year, late fall is best, after aeration.
How often you will need to have your lawn de-thatched depends mostly on what type of grass you have in your yard. Some type of turf grass produce less lawn thatch, while other types of turf grass produce more.