Mulching Mowers - Grass Clippings As Fertiliser

Q

I've been researching lawn mowers and found that some are sold as mulching lawn mowers that feed clippings back into the lawn for fertiliser. Is this true, are these mowers any good, and are grass clippings a good fertiliser?

A

Mulching lawn mowers are a traditional rotary lawn mower which has been slightly redesigned to have four mower blades and a chassis design that will spin the grass clippings through the blades several times before pushing the chopped up clippings back into the thatch layer of the turf.

These fine grass clippings will quickly decompose and disappear within a few days, leaving behind the nutrients and moisture they contain. The main components of the grass clippings being Nitrogen and Water, which are both essential to good lawn health.

In these respects, recycling grass clippings back into the lawn is a good idea to practice, being aware that a lawn will require many other nutrients to remain in the best of health. So a year round fertilising program is still important, regardless of whether we use a mulching lawn mower or not.

The only cautionary factors to keep in mind here are that long grass cannot be mulch lawn mowed, as the clippings will be far too large to break down and be effective - so regular lawn mowing is very important. The second thing to keep in mind is that if mulching lawn mowing is practiced year round, then this can contribute to a build up of organic matter within the thatch layer of the lawn, which may then require vertimowing / dethatching more often.

Mulching lawn mowers really are a great new addition to the lawn mower family. Use all the time for lawns in poor health, and less often for lawns in very good health - alternating between using a catcher and mulch mowing between services, and never use on long grass.