The Benefits of Mulching Lawn Mowers – Complete Guide with Pros & Cons
What do mulching lawn mowers do? Mulching is a method of cutting your lawn, without collecting the grass cuttings, and allowing the cuttings to be mulched back into the lawn. The grass cuttings are chopped more finely by a lawn mower equipped with either a mulching plug or a dedicated mulching mower. The benefits of mulching are the mulched grass clippings are forced back into the lawn and not collected, this saves time, is more environmentally friendly and as the grass decomposes it releases nitrogen and other nutrients into the soil, fertilising your lawn. Also, as grass is 80% water, the decomposed grass adds moisture into your lawn. As a result, a mulched lawn is healthier, greener and requires less watering.
Introduction to Mulching
So what is mulching and why is it something you need to consider when purchasing a lawn mower?
Having reviewed so many lawn mowers over the years, I am seeing an ever increasing interest in mowers that have the ability to mulch your lawn cuttings as opposed to, or in addition to, collecting them. I am regularly receiving questions and queries about these mulching mowers and more generally the process of mulching your lawn. There is so much confusing and contradictory information out there that can cause confusion, this is particularly true when articles are written outside of the UK. The UK has very specific circumstances, such as the weather conditions, that will affect the advantages and disadvantages as to whether or not mulching is the right choice for you and your lawn.
Of course, it wouldn’t be British weather without rain, and lots of it. Rain comes and goes, but it’s rarely gone for long. Add to that the fact that damp summers are way of life in the UK, then the importance of always being ready for rain in your garden becomes clear. Having said that, the last two years’ summers in the UK have seen very dry periods of several months allowing lawns to dry out and become barren patches of straw and dust.
A mulching mower is a valuable asset in helping you adjust your mowing regime to make sure your lawn is rain-ready, dry-ready and mulch-friendly.
Thankfully, mulching lawn mowers can make a huge difference in keeping your lawn and garden area looking verdant and vibrant all year round – and I’ll be telling you how.
In light of the increased desire to become more environmentally friendly by using organic methods in our gardens, and the way in which mulching can help you achieve this, I have written this article that I hope will help you decide if mulching your lawn is a feature worth considering when purchasing your next mower.
In this blog post I will cover topics based on mulching questions, I am frequently asked, specific to conditions and mowers available here in the UK. In summary, I will cover the following:-
- What is Mulching?
- How Do Mulching Mowers Work?
- Is Mulching Good for The Lawn and Why?
- When Should I Mulch My Lawn (And When Not To)?
- Are Mulching Mowers Good for The Lawn?
- Do I Have to Cut More Often with a Mulch Mower?
- Are There Any Downsides to Mulching?
- What Are the Best Mulching Lawn Mowers – What Are the Options?
- Multi Purpose Mowers or Dedicated Mulching Mowers?
- What Is A Mulching Kit and Can I Add One to My Mower?
- Who Are Mulching Mowers Best For (And Who Are Not)?
- Common Myths About Mulching Lawn Mowers
- Pro and Cons of Mulching & Mulching Mowers
- Best Mulching Mowers 2020
- Mulching FAQ’s
What is Mulching?
Mulching is a method of cutting your lawn without collecting the clippings but allowing them to return to the soil where they will quickly decompose. This method returns valuable nutrients (i.e. nitrogen) and moisture into the soil and promotes a more healthy, greener and more dense lawn. You will need either a mower with a mulching option (more on this later) or a dedicated mulching mower. I will cover both these options later in this article.
Mulching may not always be appropriate and I will cover why this is later, but if you do mulch your lawn you will gain the following benefits:-
- Healthier, greener and more dense lawn
- Reduces thatch and moss
- Less likely to dry out in hotter periods
- Saves time emptying the collection bag (up to 30% quicker)
- Environmentally friendly – use less fertilisers and water
With all these benefits why would anyone not mulch the lawn? This is why interest in mulching has become a hot topic over the last couple of years and the demand for mowers that mulch is steadily increasing.
Before you rush out to purchase a mower that mulches, there are a few things you need to consider as mulching may not always be the best option. Continue reading to learn more about mulching and some of the issues and circumstances when cut-and-collecting the cuttings may be a better option. It’s my opinion that having a mower that can mulch and also cut-and-collect is the best option here in the UK due to the wetter weather conditions. That’s not to say that a dedicated mulching mower does not have its advantages and a role to play. I discuss more about the types of mulching mower options later in this article.
So now you know what mulching is and the benefits it offers, let’s take a quick look at how it works.
How Do Mulching Mowers Work?
As the name would imply, a mower that has the ability to mulch is optimal for mulching your lawn. It is built in such a way as to allow lawn clippings to filter back into the base of the turf, instead of collecting them in a grass collection box. The best mulching mowers grind up the green waste and push it back into the soil. This allows you to maintain a continuous mulch cycle and completely organic lawn care regime which, as we’ll see, can be highly beneficial for your lawn.
When using a traditional cut-and-collect mower, the grass is cut once and forced through the grass collection chute into the collection bag. Now, imagine the chute is blocked using a mulching plug and the cuttings are spinning around and around in the deck of the mower. This cycle continues until the grass cuttings are so small they are pushed out from the bottom of the mower and deep down into the lawn. That’s basically it! A mulching mower is like a big kitchen blender chopping the cuttings into increasingly smaller pieces. Why is this important? The smaller the cuttings, the quicker they will decompose down releasing the nutrients and moisture into the lawn. Having small cuttings also ensures that they are able to find their way deeper into the lawn and are not picked up on shoes or bare feet and transferred to paths and into the house.
Remember, the longer the grass the more work the mower has to do to cut the clippings into smaller pieces. Therefore, always follow the “one third” rule. Only ever cut one third off the length of your lawn to ensure your mulching mower is not given too much to do and starts to clog up and push clumps of grass cuttings into the lawn. Not letting your lawn grow too long and following a frequent cutting programme is always a good idea when mulching any lawn.
The goal of mulching is to improve soil quality. It is able to do this in many ways, ranging from keeping the soil cool to adding nutrients back into the soil, retaining moisture during hotter periods and keeping it fertile and healthy during wetter periods, the latter of which is obviously quite important for UK lawn owners.
Take a look at the video below to see how mulching works.
Is Mulching Good for The Lawn and Why?
The simple answer is yes! For decades golf clubs have been cutting the fairways and greens without collecting the grass cuttings. This is the same method as mulching your lawn. We would all love a lawn that looks as good as a golf course green, so what better recommendation for mulching than this?
Obtaining a green lush lawn can be time consuming and costly. Many gardeners have given up and have outsourced the task to a lawn maintenance company who will periodically treat your lawn with chemicals. This is not ideal as it’s expensive, not environmentally friendly and it’s still down to you to cut the lawn regularly.
Mulching allows you to cut your lawn as normal (but saving time collecting and emptying the cuttings) whilst fertilising (feeding) and protecting your lawn from dry periods, moss, thatch, pests and disease.
The small particles of grass are forced deep down into your lawn where they decompose within a few hours and release nutrients such as nitrogen and phosphate. These nutrients are then transferred into the soil via micro-organisms organically fertilising your lawn without you having to use expensive lawn services or costly artificial fertilisers. Mulching is also pet and child friendly unlike artificial fertilisers.
A blade of grass is 80% water, so this moisture is also released into the soil providing much needed water reserves during the drier hotter periods of the summer.
There are myths suggesting that mulching can cause thatch or moss in your lawn; this is simply not true. More information about this can be seen below in the “Common myths about mulching” section.
So yes, there is no disputing it, mulching can be extremely good for the health and condition of your lawn.
When Should I Mulch My Lawn (And When Not To)?
Knowing when it is the right time to mulch your lawn is important. We need to remember what we have learnt about mulching so far to know when it is the best time to mulch. As I said above a mulching mower is like a big kitchen blender and needs the grass cuttings to fly around the deck to cut them smaller and smaller.
If the lawn is wet or very damp, the mulching mower will start to clog up and will NOT be able to freely disperse the cuttings resulting in clumps of grass being deposited on the lawn (not good!). In this situation it would be best to let the grass dry out for a day or two, or simply cut and collect the cuttings on this occasion.
This is the main reason I believe a mower that can both cut-and-collect and mulch is a better option for gardeners here in the UK. You will have the ability to adjust your cutting method based on the weather conditions.
Mulching is best carried out when the lawn is relatively short and dry. This means you will need to follow a regular mowing schedule as you are only ever going to cut one third of the grass at any one time (more about how often you need to mulch later). If you let your lawn grow longer for several weeks before cutting, then perhaps mulching is not for you.
Having said that, we know that cutting the lawn too short also contributes to problems. Blades of grass need to absorb as much light and nutrients as possible to keep in reserve for more challenging growing conditions such as dry periods.
Your lawn doesn’t need to be as short and tidy as a golf course. That’s unrealistic for a variety of reasons, not the least of which being that golf courses have far more natural and financial resources at their disposal to aid that end.
Other times when mulching may not be the best method, is when you have weeds in your lawn that are seeding such as dandelions and/or crabgrass. It would be better to deal with the weed issue first before mulching as you are simply going to spread the weed problem, alternatively use cut-and-collect until the weed issue is resolved. The same is true if you have a thatch or moss issue in your lawn, mulching may exacerbate the problem, so again, resolve the issue first before mulching.
So by having a mower that allows you to both mulch and cut-and-collect gives you the best of both worlds and ensures you always have a great looking lawn. At the end of this article I have listed my top mowers that have the added ability to mulch the lawn.
Are Mulching Mowers Good for The Lawn?
Since you don’t have to empty the box, a mulching lawn mower can also be a good choice for cutting down on the total amount of garden waste and time spent cutting your lawn. You also won’t have to worry about constantly replacing the bag or making your way to the compost heap if you are tasked with cutting a large lawn.
Another benefit about modern mulching mowers is that they push the freshly-cut grass right back into the turf. If you have ever tried to mulch before, you know that two potential downsides are the possibilities for unsightly clumps of grass and a lack of aeration if mulching in wet conditions. The former can make your lawn look a bit messy and spotty, while the latter can block the air flow to the soil and roots of your grass, which can harm your grass’s health and potentially promote rot.
Using a mulching mower correctly and at the right time is the key to successful mulching, resulting in a lush, green and healthy lawn that’s the envy of your neighbours. Not only this, mulching your lawn while you’re mowing will cut down on the time it takes to cut while simultaneously providing all the benefits to your lawn explained above.
Mulching mowers are especially important in the UK due to our wet and changeable climate. Excessive rain can make mulch heavier and cling together more, making it harder to move and separate, so choosing the right time to mulch is important (see “When to Mulch” above).
Do I Have to Cut More Often with a Mulch Mower?
The short answer is, it depends on how often you cut your lawn anyway.
As stated above, you will not be able to let the grass grow too long and expect to be able to mulch the lawn. You will most definitely need a regular cutting schedule during spring and summer.
So how often will you need to mulch the lawn to get the best results?
On average in the UK, the grass should be cut weekly during the spring and reduced down to a biweekly basis during the summer. This will vary slightly depending where you are located in the UK, and there may be areas that need to cut as much as twice per week.
If you’re someone who is looking to mulch an entire huge field in one go, and only want to cut twice a year then mulching is definitely not for you. However, most of us have far smaller lawns to tend to, so you’ll most probably want to cut on a more regular basis and stick to a frequent timetable.
As indicated by those aforementioned weekly trips to the compost pile, many gardeners who choose to mulch do so on a weekly or biweekly basis. A mulch mower makes this even easier, since according to a recent survey, during the growing season, most of us mow the lawn once a week anyway, and these mowers mulch as they go.
The fact that your mower mulches as well as it mows does not mean that you’ll need to cut your lawn more often, simple once a week lawn-care is the rule, and mulching mowers are perfect for that. What’s more, part of the point of a mulching mower is to streamline the process.
Are There Any Downsides to Mulching?
Simply put, there are no real downsides to mulching. As long as you follow a cutting schedule and mulch when the conditions are correct as explained above, then there is no reason why mulching will not provide the benefits I have discussed.
You may pay a little more for a mower that has the ability to mulch, but the benefits far outweigh the additional cost. For example, if you were to purchase a Bosch Rotak 37 LI Ergoflex mower, the optional mulching plug would cost around £15 extra and is readily available on Amazon. To give an example of a corded mower that has the mulching ability built in, the Mountfield Princess 34 mower costs around £100.
You can see why the demand for mowers that mulch are becoming more popular; there really are very few downsides to mulching your lawn if done correctly.
What Are the Best Mulching Lawn Mowers – What Are the Options?
When choosing a new mower, already many decisions need to be made such as – do I go for a petrol, corded, cordless or even a robotic mower and what deck size do I need?
Well the good news is that mulching mowers do not need to add to the stress of choosing the best suited lawn mower, they are available in all of the above types. Robotic mowers by design only have the ability to mulch the cuttings and are ideal as they are mowing for long periods on a regular basis, so the grass never has a chance to grow too long.
Multi Purpose Mowers or Dedicated Mulching Mowers?
As stated earlier, there are dedicated mulching mowers that do not have the ability to collect the grass cuttings. Then there are mowers that come with the ability to block the grass collection chute with a mulching plug turning it into a mulching mower.
Naturally the mower designed only for mulching will be more efficient and precise at mulching, but you then lack the ability to switch to the cut-and-collect method if needed, say during wetter periods.
A dedicated mulching mower will also allow for a side discharge, this means it is able to mulch longer grass as the deck does not get clogged with clumps of grass.
Remember it’s not just about blocking the grass collection chute, the blade on a mulching mower needs to be designed in a way that blows the cutting around the deck just like a blender. This specially designed blade does not negatively affect the normal cut-and-collect method of cutting, and actually helps the collection of the clippings. Any mower is NOT going to collect 100% of the grass cuttings anyway, so for me, it just makes sense to have a mower that is capable of both.
At the end of this article I have listed what I believe are the best mulching mowers available to the domestic UK market today. So as you will see, it does not matter if you prefer a petrol or electric mower, there is always a mulching option available to you.
To help with choosing the best mower for you and your lawn, I have created a complete guide to buying a lawn mower that can be downloaded here. A Helpful Illustrated Guide to Buying a Lawn Mower.
My guide covers everything you need to know about choosing a mower, and which is best for you and your lawn. Everything from what type of mower (petrol, electric, cordless etc), power, self propelled, deck size, features and so much more.
What Is A Mulching Kit and Can I Add One to My Mower?
A mulching kit is an add-on that can be attached to certain mowers if you wish to convert them for mulching purposes. They usually contain a mulch plug, mulching blade, and sometimes additional deflectors to deflect the clippings outward so as to make them easier to re-cut before they are pushed back into the soil. However, they are not compatible with every type of lawn mower, so you’ll want to make sure that any kit you purchase is compatible with your lawn mower’s model.
Who Are Mulching Mowers Best For (And Who Are Not)?
As mentioned earlier, mulching is best for those that can, more or less, stick to a regular cutting schedule for the reasons stated above. If you are the type of person that will only ever cut the lawn when it’s sky high and overgrown, then mulching is not for you.
If however you want to have a lush and healthy lawn, want to do your bit for the environment and save some time and money in the process, then you should seriously consider the option of a lawn mower that can mulch. Yes, you will have to cut the lawn every fortnight in summer, but hey, this is what you would do anyway if you wanted a well tended and usable lawn.
Common Myths About Mulching Lawn Mowers
The following are common myths about mulching your lawn that have been going around for years:-
Grass cuttings everywhere
Not true, the grass cuttings are so fine and rot down so quickly that this will not be an issue. Remember cut-and-collect only collects 80% of the cuttings, so it is more likely to leave cuttings on your shoes than mulching.
Causes thatch and moss
Absolutely not. If you have a thatch or moss issue, then this is not as a result of mulching. Resolve the issue and resume mulching as this will help to prevent a re-occurrence of the thatch or moss.
Mowers that mulch cost too much money
Not the case, as detailed above, an electric mulching mower can be yours for under £100.
Mulching does not help improve the condition of the lawn
It’s a scientific fact that mulching and the microbial activity helps improve your lawns health and appearance.
Pro and Cons of Mulching & Mulching Mowers
Pros – What are the benefits of a mulching mower?
- Healthier, greener and more dense lawn
- Reduces thatch and moss
- Less likely to dry out in hotter periods
- Saves time emptying the collection bag (up to 30% quicker)
- Environmentally friendly – uses less fertilisers and water
- Cost savings on lawn care, fertilisers and water
- No garden waste produced
Cons – What are the disadvantages of a mulching mower?
- Regular mowing schedule is required
- Not suitable for long grass – cut and collect first then mulch
- Sometimes need to be purchased as an optional extra
I hope this article has enlightened you to the benefits of mulching, what’s involved in getting started and making it a success on your lawn. If you do have any questions, please ask using the comments box below and I will be happy to answer.
Please also let me know your experiences of mulching the lawn and any tips or tricks you would like to share with my visitors.
Best Mulching Mowers 2020
Electric Corded Mulching Mowers
Cordless Battery Mulching Mowers
Petrol Mulching Mowers
To see more in-depth reviews of the best mulching lawn mowers please see my article – Best Mulching Lawn Mower 2020 – UK Reviews and Buyer’s Guide
Does mulching cause thatch or moss?
No, mulching does not cause thatch or moss, in fact it will help prevent it. Mulching will also not help to reduce any thatch or moss issues with your lawn (will have to be sorted out separately). The issues of thatch and moss are caused by a variety of factors including poor soil conditions, over watering, over fertilising, too shady areas etc.
Can I mulch when the grass is wet?
You can, but I would not recommend it as this could cause the mulched clippings to bind together forming clumps of grass.
What about leaf collection?
Your mulch mower should be able to mulch leaves and force them back into the soil along with the grass. Leaves are also a good source of organic matter. Just make sure not to over-do-it with large quantities of leaves.
Do I have to cut more often with a mulch mower?
Not more often, just on a regular basis to ensure that the lawn doesn't grow too long.