How-to Guides

All About Mulching: What, Why, When & How

Mulching your lawn is one of the smartest ways to save time, reduce garden waste, and feed your grass all in one go.

But how does mulching actually work? When should you do it? And when is it better to hold off? In this guide, Snapper Sam walks you through the benefits of mulching, how to do it properly, and what to keep in mind when choosing a mulching lawn mower or kit.

What is mulching?

Mulching is the act of covering your garden soil or lawn with a layer of garden debris such as leaves, garden waste, compost or grass clippings.

When you mulch the lawn, you’re basically mowing as usual. But instead of collecting the grass clippings in a bag, they’re cut into fine particles and spread directly back onto the lawn. This creates a thin, even layer of mulch across the soil surface. To do this, you’ll need a mulching lawn mower or a mower with a mulching function.

This shredded layer of lawn clippings helps to feed your lawn, meaning you can often reduce your use of synthetic fertilisers. It also helps to conserve moisture by reducing evaporation, especially during dry spells. And because the mulch breaks down fairly quickly, your lawn stays looking clean and tidy.

Why mulch?

There are several reasons why mulching your lawn is a smart, low-effort way to improve your lawn’s health and make your gardening routine easier.

Care for your lawn the natural way

Mulched grass gives the lawn natural nutrients. It acts as an organic fertiliser, made up of finely shredded grass clippings.As this organic matter breaks down, it feeds the soil and supports healthy root growth. In addition, a mulch layer helps to suppress weed growth and protects the soil surface and soil life from extreme weather conditions. Think of this as protection from extreme temperatures and reduced moisture loss during dry spells.

It also encourages beneficial microbial life in the soil, which plays a key role in maintaining long-term lawn health. Over time, mulching improves soil structure, helping your lawn grow thicker, stronger and more resilient.

And because it all happens as you mow, mulching fits neatly into your existing routine

Great for your wallet

Because the fine grass clippings from a mulching mower function as a good source of nutrients, less fertiliser needs to be purchased. That’s good news for your wallet, and even better news for the environment, as it reduces the use of chemical products in your garden.

Over time, you'll also spend less on weed treatments and other lawn-care extras, since regular mulching helps strengthen your lawn and makes it more self-sufficient.

Saving work and time

After mowing with a regular lawn mower, you need to clean up the loose grass clippings from the lawn or empty the collection bag. When you're mulching, the grass clippings are spread across the lawn. So you don't have to clean up and dispose of the clippings yourself.

Mulching also reduces the need for weeding. By regularly cutting weeds short, they don’t get the chance to grow and spread further. And because the shredded clippings break down quickly and settle neatly between the grass blades, you won’t be left with clumps or unsightly piles.

When to mulch?

Mulching works best when your grass is actively growing and conditions are dry enough for the clippings to break down properly. Here’s when to do it for the best results:

Start in spring, but not too early

Begin mulching once your lawn has started growing again after winter dormancy. In most cases, that’s around mid to late spring. You want to see steady, healthy growth before switching on the mulching function. If the grass is still patchy or thin, collect the clippings until things fill in.

Continue through summer

Late spring and summer are the ideal times to mulch grass. Your lawn is growing quickly, the soil is warm, and the nutrients from mulched clippings can make a big impact. Just make sure to adjust your mowing schedule, as grass often grows faster in summer.

Mow little and often

For mulching to be effective, mow once or twice a week depending on how fast the grass is growing. This keeps the clippings short and light, so they don’t sit on top of the lawn or form clumps.

Follow the “one-third rule”: never remove more than a third of the grass height in one go. That means you’ll usually be cutting the grass down to about 4 or 5 cm.

Always mulch when the grass is dry

Mulch only when the grass is dry. Wet clippings tend to clump together instead of spreading, which can smother the lawn and block airflow. Dry grass allows the mulch layer to spread evenly and break down more quickly.

What about autumn?

You can continue mulching into early autumn, as long as the grass is still actively growing and the weather is dry. This helps return nutrients to the soil before winter and supports root strength.

But as temperatures drop and moisture levels rise, grass growth slows down and lawns stay damp for longer. Mulching in these conditions can lead to clumping, poor decomposition, and even lawn damage from trapped moisture.

When not to mulch?

Despite its many benefits, mulching is not suitable for every lawn. Here are a few times when you’re better off switching to a regular mowing setup:

Avoid mulching wet grass

Mulching only works when the clippings are light and dry enough to spread evenly and break down quickly. When the grass is wet, the clippings clump together instead of scattering. They stick to the underside of the mower deck, fall in heavy clumps, and block airflow and sunlight.

Instead of feeding your lawn, these soggy piles sit on top of the grass and start to rot, which can lead to yellow patches or fungal problems.

Note that if your lawn is mostly shaded, the grass will stay wet for longer after rain. In that case, it is better to maintain your lawn with a conventional mowing set-up.

Don’t mulch when the grass is too long

If you haven’t mowed in a while and the grass has grown tall, mulching can do more harm than good. Even when finely shredded, the volume of clippings becomes too much. The mulch builds up in a thick layer, blocking sunlight and airflow. This weakens your grass and creates the perfect environment for disease and thatch.

In these cases, start with a regular mow to bring the height down, and return to mulching once the lawn is back under control.

Skip mulching if you can’t mow often

Mulching relies on routine. If you wait too long between mows, the grass grows too tall, and the mower ends up producing large, heavy clippings. Even if they’re shredded, the volume is too much for your lawn to absorb, and you’re left with a thick layer sitting on top.

This smothers the grass and prevents healthy regrowth. Worse, if there are weeds in the mix, irregular mulching can actually help spread their seeds across your lawn.

How does mulching work?

When you mulch with a Snapper mower, you’re not just cutting the grass once and dropping it. The process is a bit more clever than that.

Here’s what happens under the deck:

The grass is cut just like it would with a regular mow.
Instead of being discharged, the clippings are kept circulating inside the mower deck.
The airflow inside the deck tosses the clippings around so they pass through the blades again and again.
With each pass, they’re chopped into finer and finer pieces.
Once the clippings are small enough, they are scattered evenly onto the lawn.

How to mulch your lawn (the right way)

Want to get the most out of your mulching mower? Use this quick checklist:

Mow once or twice a week during the growing season
Regular mowing keeps clippings short enough to break down quickly.
Never cut more than a third of the grass height
Taking off too much at once stresses the grass and causes clumping.
Only mulch when the grass is dry
Wet clippings stick together and smother your lawn.
Use a mower with a proper mulching function
These circulate and re-cut the grass into finer particles.
Keep your blades sharp
Clean cuts help mulch break down faster — blunt blades tear and leave a mess.
Mow at a steady pace
Rushing can cause uneven distribution and overload the deck.
Clean your mower deck frequently
Built-up grass affects airflow and mulching performance.
Inspect your results
If clippings are sitting on top of the grass, adjust your frequency or height.

Choosing the right lawnmower

The best mower for your lawn depends on how often you mow, how you like to dispose of clippings, and how much flexibility you want in your mowing routine.

If you’re planning to mulch regularly, it’s worth choosing a mower that’s designed for the job. Snapper offers a wide range of zero turn mowers, lawn tractors or cordless lawn mowers which can be set up for mulching.

If you prefer to bag or discharge your clippings, no problem. Then check out our zero turn mowers, lawn tractors or cordless lawn mowers with other cutting configurations that are better suited for your lawn.

Mulching FAQs: Your Top Questions Answered

Is mulching good for your lawn?

Yes! Mulching is one of the easiest ways to keep your lawn healthy. It returns valuable nutrients like nitrogen and potassium directly to the soil, improves moisture retention, and reduces the need for synthetic fertilisers. Done correctly, it supports thicker, greener growth without adding any extra steps to your mowing routine.

How often should I mulch my lawn?

It depends on how quick your grass is growing, but generally once or twice a week during the growing season is ideal. The key is to mow frequently enough that clippings stay short. That way, they decompose quickly and feed the lawn instead of sitting on top.

Does mulching cause thatch build-up?

No, that’s a common myth. Thatch is caused by a build-up of dead roots and stems, not by mulched clippings. If you mulch with sharp blades and mow regularly, the clippings will break down quickly and enrich the soil rather than smother it.

Can any lawn mower be used for mulching?

Not quite. You’ll need a mower with a mulching function or a mulching kit installed. These are designed to recirculate and re-cut grass clippings into finer pieces before dropping them back onto the lawn. Standard mowers won’t produce the same clean, even results and may leave visible clumps behind.

What does a mulching kit or plug do?

A mulching kit typically includes a plug that blocks the discharge chute, along with special blades designed to chop grass more finely. The plug keeps clippings inside the deck long enough to be cut multiple times, so they settle back into the lawn rather than being thrown out through the side.

Can I mulch a new lawn?

It’s best to avoid mulching very young grass. Wait until the lawn is fully established, and make sure the mower won’t tear the tender grassblades. Once it’s strong and growing consistently, you can gradually introduce mulching.

Can I mulch the first mow of the season?

Only if the grass is dry and hasn’t grown too long. The first cut is often heavier, so you may want to collect clippings the first time, then switch to mulching once the lawn is under control.

Can I mulch leaves into my lawn?

Yes, but do it with care. Light, dry leaves can be mulched like grass. If there’s a thick layer of wet or matted leaves, it’s better to collect or compost them instead.

Does mulching spread weeds or moss?

Not if you mow regularly. Inconsistent mowing can give weeds the chance to go to seed, and mulching those seeds can spread them across your lawn. But when done correctly, mulching actually helps suppress weeds by keeping your lawn dense and healthy. Mulching moss is not recommended, as it can encourage regrowth.