Thatch is the organic matter that builds up between the soil and grass blades. Excessive thatch prevents much of the water from reaching the soil. If you use fertilisers, the fertiliser may not reach the roots as well. Signs of too much thatch include witling grass blades, grass that is brown on the bottom and grass that is prone to disease, insects and winter kill. Verticutting, also called dethatching, is a process used to remove thatch. Therefore, if you want to restore your lawn back to health, verticutting is often one of the first steps to do so successfully.
Examine your lawn for excessive and harmful thatch build-up. Walk on it to see if it feels springy, like a plush carpet, a common sign of too much thatch, or dig into your grass and soil to measure the thatch between the green grass blades and soil. Less than 1/2 inch of thatch is little concern and can actually help your grass. If the thatch build up is over 1/2 inch, vericutting your lawn may be beneficial.
Set the blades on the verticutter at 2 or more inches. Have the rental agent show you how to do this or have him do it for you, especially if the owner's manual was not provided for you.
Verticut your lawn similar to the way you mow your lawn, in rows. For lawns with an excessive build-up, follow up with an aerator. Remove the thatch when finished.
Prevent thatch in the future to minimise the need for verticutting and to grow a healthy lawn. Water your lawn deeply and less frequently, use a slow-release nitrogen fertiliser and mow often. Thatch is not caused from failure to rake up grass clippings.
Ask your local turf specialist or county extension office to learn the best time of year and type of blades and settings for your lawn variety in your climate and elevation. After verticutting is a good time to overseed your lawn to fill in any bare areas. If your thatch is built up is 1 to 1-1/2 inches, then you may have to verticut you lawn again later in the year.
For lawns with more than 1 1/2 inches of thatch, it may be best to remove the grass and thatch, and replant your lawn.