Unless you live in the deep South, grass clippings should be left on the lawn where they are cut.
The growing tips of plants use more nitrogen than the rest of the plants so these growing tips contain a significant amount of nitrogen
By leaving them to decompose on the lawn, that nitrogen will be made available to the other grass plants.
If you take away the clippings, you’ll have to pay money to purchase nitrogen to replace
Frankly, grass clippings do not add to thatch problems.
Thatch is a total management problem.
But let’s examine the data.
Grass is mostly cellulose – a material that is easily and reliably broken down by soil microorganisms.
Thatch is mostly composed of lignin, a component of grass crowns (not leaves), stolons and rhizomes. Grass clippings are pretty much irrelevant to the creation of thatch. The way you mow your lawn, feed and water determines thatch.
Decomposing clippings feed soil microorganisms and keep them alive and healthy to fight off lawn pests and diseases. Removing this food source reduces the number of beneficial organisms on your lawn that are trying to help you.
Tentatively note that some researchers believe decomposing grass produces a chemical that prevents crab grass from germinating. This is not yet confirmed.
Clippings For Compost
What you probably want to know though is whether clippings make good compost.
They make excellent compost.
Their composition is such that they will compost all by themselves in a very fast and efficient manner without the addition of any other material. And yes, they can be added to the compost bin unless you’ve been spraying chemicals on them.
Spraying chemicals on lawns is a advertising-supported activity that is about to go the way of the dinosaur. Check out my organic lawn care ebook for further information.
So leave the grass clippings where they do the best thing in the garden – on the lawn.
Go have a beer and celebrate doing less work and getting better results!