Then self-bagging lawn mowers were invented, and people were told to bag their grass clippings.
In most cases, the answer is easy: Leave the grass clippings on the lawn.
Leave the grass clippings to save yourself time and energy. Clippings return valuable nutrients to the lawn in the form of mulch and result in a more luxurious and healthy turf. Done correctly, mulching nourishes your lawn with beneficial nitrogen, phosphorus, and potassium nutrients.
When mulching, if you find that your mower is leaving behind large clumps of grass, turn off your mower and adjust your blade height. Grass clippings should be one inch or less in height. If you experience a trail of grass clumps, attach your bag and proceed mowing. You can always distribute your clippings with a lawn rake once you have finished mowing.
Penn State University’s Center for Turfgrass Science, defines “thatch” as a loose, intermingled organic layer of dead and living shoots, stems, and roots that develops between the zone of green vegetation and the soil surface.
Thatch builds up when turf produces organic debris faster than it can break it down.
Harmful thatch build up results from using pesticides, overusing synthetic fertilizers and improper maintenance—mowing too low or too infrequently.
Use organic fertilization, mow high and regularly, with a sharp blade, and your grass clippings won’t contribute to thatch build up because soil microorganisms easily break them down.
Maintain your lawn regularly and properly, and thatch does not build up.
Is bagging ever OK?
There are some circumstances when collecting your grass clippings is warranted:
- If you see signs of lawn disease, pick up the grass clippings to avoid spreading the fungus.
- If you want to use you grass clippings for garden mulch, bag or rake the clippings into a compost pile. As additions to a compost pile, lawn clippings are excellent because of their relatively high nitrogen content.
- If your mower is clumping (because you are trying to cut too much at once, or because your blade is not sharp enough), it is best to bag the grass clippings.
Which leads us to:
The key to mulching is a good lawn mower. Ensure that your blades are sharp to help your mower cut each blade of grass into finer, more lightweight blades of grass. Don’t take too much off the top at one time. Cut the blades into small pieces so that they decompose easily (grass clippings are 85% water). A rule of thumb is to take off the top 1/3 of the grass blade when you cut it.
Learn more about proper turf maintenance here: Sustainable Lawn Mowing