What is a mulching lawnmower?

A mulching lawnmower doesn't collect or discharge the grass clippings, but instead repeatedly cuts the clippings so small into what's called mulch. The tiny clippings are then deposited back into the lawn, leaving a finished appearance as if the clippings had been collected. The mulched clippings decompose and act as fertiliser for the lawn.

For a mulching lawnmower to achieve this, a special type of mower blade is used called a mulching blade. The design and shape of the mulching blade creates airflow which keeps the clippings inside the cutting deck, allowing them to be continuously cut and broken down into mulch.

Dedicated mulching lawnmowers don't have a grass bag or discharge chutes, and the deck is fully contained.

Are mulching lawnmowers a good idea?

Used properly, a mulching lawnmower will boost the health of your lawn making it lusher and greener.

Benefits of mulching lawnmowers:

• Mulching is a more environmentally friendly method of dealing with the grass cuttings as they don't need to be collected and disposed of. You'll also never have to stop halfway through mowing to empty your grass bag.
• Mulching your clippings provides your grass the fertiliser it needs to be lush and green, in a natural way.

However, there are some things to be aware of:

• In order for your mulching mower to be able to break down your grass clippings into mulch, the grass can't be overly long. This means in the peak growing season you will be required to cut your grass at least once a week, if not more regularly.
• Just as you shouldn't mow your grass when wet, this is equally the case with mulching. In wet conditions the clippings can clump together and your mulching mower won't be able to break them down.
• If your lawn has weeds, the mulching process will disperse them across your lawn where they will spread. To prevent this from happening you should be collecting and disposing of the cuttings with a lawnmower that collects.

By properly mulching your lawn with a mulching lawnmower, you will start to see the benefits of the mulched clippings in a matter of weeks. 

Collection, discharge and mulching lawnmowers

Dedicated mulching lawnmowers are designed without a grass bag or a discharge chute, and will always give the best mulching performance. There are also some standard collecting lawnmowers which can be converted into being able to mulch.

This is achieved by using a mulching kit, which includes a mulching blade and a mulch plug (which blocks the chute that leads to the grass bag). The grass bag is then not required and can often be removed.

If you ever want to go back to collecting or discharging the grass clippings, you simply remove the mulch plug and, if necessary, switch out your mulching blade for your standard blade. The cuttings are then lifted into the chute and into the grass bag.

Popular lawnmowers which can mulch, collect and discharge grass cuttings:

• Mountfield SP555 V Lawnmower
• John Deere X350R Lawn Tractor
• Honda HRX 537 VY Lawnmower
• Husqvarna R112C Rider (discharge and mulch only)

If you are looking for some help in choosing a lawn mower, read our lawn mower buying guide.