How to Mulch Grass Clippings

The easiest way to start mulching is to take the grass catcher off the lawn mower. This tip is so important that it bears repeating. Take the catcher off your mower!

Your mower service shop should be able to put a trap door over the discharge end if your mower does not already have one. For conventional side discharge mowers without a trap door, mulching may require a bit of raking following mowing to break up the rows of clippings.

To avoid raking the entire lawn, mow from the outer edge in ever-smaller circles toward the center, making sure that the side discharge mower is “walking” or blowing the grass clippings ever closer to the central point. In this manner, clippings are chopped several times and most fall between the blades as mulch. The few that are left near the center can easily be raked and placed into the compost bin or spread in the garden.

Mulching mowers have become quite popular in recent years, and dealers proudly display their new features. Advertising campaigns are helping convert homeowners to these new “zero discharge” mowers.

Mulching mowers are designed differently from conventional mowers with closed trap doors:

• Mulching mowers lack a discharge point and a catcher. 
• Mulching mowers require more horsepower to cut and re-cut grass.

The special blade not only cuts, it also acts as a vacuum and fan that circulates the clippings back to the blade for additional pulverizing. The air pressure then forces the chopped clippings downward into the lawn. Even replacing your regular cutting blade with a mulching blade can turn a regular mower into a better mulching mower.

Mulching mowers require a lawn that is not overly wet and has not been left too long between cuttings. The height of the grass should be somewhat higher than typical settings for bagging mowers. The lawn is best cut when the grass is one-third higher than the height of the blade.

For the average lawn, if the grass is left at two inches following mowing, the grass would be cut when it reaches three inches. The lawn must be mowed more often than with conventional mowers, but the time actually spent in the yard is less because there is no need to continually stop and empty the catcher. Mulching mowers should be used every five to six days, instead of every week.

Cutting grass higher with only one-third the blade height is easier and faster than cutting overgrown grass. Fertilizing can be decreased since grass clippings contain four percent nitrogen and act like a time-release fertilizer when they are returned regularly to the soil. Grass clippings return to the soil to form organic humus that helps hold water, while keeping the soil loose and aerated.