For warmseason grass, the ideal time to dethatch is during the spring season, or the second time you mow the lawn. Before you get to it, mow the grass a little shorter than you usually do. For coolseason grass, it is preferred that you should dethatch your lawn in late summer or early fall.
You can measure the thatch by sticking a screwdriver into several spots in your lawn. Before hitting the soil, measure the amount of thatch between the soil and the grass. If there is more than one-half inch of thatch, dethatching is required.
In case the thatch is less than an inch in thickness, which is the case with small lawns usually, you can use a rake to remove it. A dethatcher has vertical blades or tines that cut into the thatch and brings it up to the lawn surface. This is known as manual dethatching and it causes the least amount of stress to plants. A rake with hard tines is used to pull thatch to the soil surface but it may not always be effective.
Based on the grass type, blades must be set certain spaceapart when using a dethatcher. You can also adjust the cutting depth. The ideal depth when cutting into the soil is less than half an inch.If your lawn only has a mild thatch, you can use a plug aerator.The aerator will dethatch the lawn in those spots where soil plugs are removed, and this way, you can prevent bare spots on the grass.
If you have a large lawn, then manual dethatching will not be convenient. Use a vertical mower instead, as it has revolving blades, the cutting depth of which you can easily adjust. This way, you can cut the thatch and ensure it comes up to the surface for easy removal. Adjust the depth based on the density of the thatch and the quality of the grass. For best results, hire a professional lawn care service like Schwartz Brothers Landscape Solutions.
After you are done with thatching, your lawn may appear messy. What you can do is rake it up and remove it, and later on use the thatch for mulching.