Moss can be a real headache in lawns. And if your lawn gets damp and shady, you’re likely to have even more of a problem. The good news is that there are some excellent products out there to keep the spongey staff at bay!
We’re going to take a look at seven of the best lawn moss killers out there today. We’ll review their good points and any not-so-good ones. And we’ll set out the factors you need to think about before you make your final choice.
So if you’re ready to say goodbye to moss in your lawn – step this way!
The Best lawn moss killers in UK
The Best lawn moss killers in UK 2023
1. Miracle-Gro EverGreen Mosskill
EverGreen Mosskill from Miracle Gro is one of the more expensive moss treatments on our list. But its effective formulation means you’ll get results fast.
Each box contains 2.8 kilograms, enough to treat about 80 square metres of lawn. That’s an area five standard fence panels wide, and the same distance long. It combines a lawn feed with a specialist moss killer to give you green, healthy, moss-free grass.
The active ingredient that gets rid of the moss is iron sulphate. That makes up just under 17 per cent of the product. The rest is a mixture of nitrogen and potassium oxide which acts as fertiliser.
It takes the form of granules, and you’ll want to distribute it in an even layer over your lawn. A spreader will make that easier to achieve. When you’ve finished, water it in thoroughly.
You should see results within seven days, often as little as 48 hours. The moss will blacken and die, and you can rake it up after two weeks. The grass will then start to grow to cover the bare patches. If you need to reseed, don’t do it until eight weeks after the treatment.
Apply the granules between April and September, when the grass will be growing. You want a day when the soil is moist but the grass is dry, and the weather is fair. Don’t spread them in drought or frosty conditions, or if heavy rain is expected.
Don’t use the treatment more than twice a year, and leave it at least three months between applications. And don’t use it on lawns less than six months old. The chemicals will be too strong for the young grass.
It’s important to keep children and pets away from the granules before they’ve been watered in. And when they have, it’s a good idea to stay off your lawn until it’s dry. Wet iron sulphate can leave brown stains on your clothes. And it’s easily transferred to paths and patios on the soles of our shoes.
Note that this is specifically designed to target moss. If you want a formula to handle weeds too, this won’t be the right choice. But take care to avoid drift onto flower beds, as it can damage other foliage.
Pros:
- Very effective at tackling moss, with results in as little as two days
- Fertilises the grass too, helping create a lush, green lawn
- Safe for areas used by children and pets, as long as they’re kept away until the granules are watered in
Cons:
- Shouldn’t be used more than twice a year, with at least three months between treatments
- Not designed to tackle weeds.
2. Green Force Lawn Feed, Weed and Mosskiller
If you need to get rid of weeds as well as moss, Green Force’s triple action formula could be the answer. It’s good value for money too. The 1.5 kilogram pack contains sufficient product to treat up to 150 square metres of lawn. And it’s about the same price as the EverGreen Mosskill.
As with most moss killers, this uses iron sulphate to get the job done. The proportion included is slightly lower than you’ll find in Mosskill, at 16.2 per cent.
You should still see the moss blacken and die within a week. You’ll be able to rake up the dead stuff between one and two weeks after application. If you’ve got particularly heavy growth, you may find you need a second treatment.
It also contains a fertiliser for your grass, with a mix of 10-2-4 nitrogen, phosphorous and potassium. That will give your lawn everything it needs to grow strong and healthy.
The weedkillers are Dicamba and Mecoprop-p. They’ll get to grips with most common lawn weeds, but you will need to give them time to work. Total weed control can take anything up to four or five weeks.
The application rate here is 20 grams per square metre. Mark out the area using string or canes, or use a spreader to get even coverage. Apply the product during the growing season, from April to September. If you can, avoid using it for four days before mowing and three days afterwards.
Make sure it goes onto the lawn when the soil is moist and there’s no frost, and water it in afterwards. Take care, though, to avoid neighbouring paths or patios. If the wet product gets onto them, the iron sulphate can leave behind stubborn brown stains.
Pros:
- Will kill both moss and weeds
- Works quickly on moss, allowing you to rake it up between one and two weeks after application
- Incorporates a good quality fertiliser for a green and healthy lawn
Cons:
- May require a second application to combat heavy moss growth
- Avoid getting the wet formula onto paths or patios, as it can stain them brown.
3. MOOWY Iron+ 2 in 1
British brand MOOWY combines a moss killer with fertiliser to help your lawn grow green and healthy. And it’s a great option if you’re looking for a treatment that can be applied during the colder months. This is designed for application between September and May.
Despite being applied outside the growing season, this also contains a fertiliser to support healthy grass. This contains nitrogen, phosphorous and potassium in the ratio 3-7-10, as well as three parts magnesium oxide.
The weather needs to be dry when you apply it. You want coverage of 29 grams per square metre. Wear gloves and old clothes when you do it – as ever, the moss killing is carried out by iron sulphate. That means that if you get it on yourself, you can end up with rusty stains. The same goes for paths and patios.
Watering the lawn afterwards will help the treatment get to work faster. If you’re expecting rain, though, you can let that do the job for you.
The moss will begin to die within a few days. Wait at least a week after treatment before raking it up. And don’t overseed the area until at least six weeks after applying the granules. The chemicals will still be in the soil and your seeds are unlikely to germinate.
There’s no weed killer here. If your lawn is suffering from dandelions, docks or suchlike, you’ll need to get rid of them separately.
But if you want to get rid of moss in colder weather, this is just what you need.
Pros:
- Kills moss and fertilises your lawn
- Designed for use in colder weather, between September and May
- Depending on the conditions, you can expect to see results in just a few days
Cons:
- If you need to get rid of weeds as well as moss, you’ll need to buy a separate product
- Watch out for rusty stains if any of the product gets onto paths or patios.
4. Tradefarmni Guard-En-Force Iron Sulphate
Tradefarmni’s iron sulphate is a very effective and economical choice. A 5-kilogram tub will give you enough product to treat between 1,000 and 1,250 square metres.
It’s most usually used between late autumn and spring. Use it though the autumn to keep the moss in check. Or between January and April, you can apply a treatment to get rid of the previous year’s growth. It will also condition your lawn and help promote verdant, healthy grass.
You’ll need to dilute it and water it onto your lawn using a garden sprayer or watering can. Use 1 or 2 grams per litre of water if you want to condition your grass.
Increase the concentration to between 2 and 5 grams per litre to get rid of moss. You can adjust the strength of the mixture according to how thick the growth is.
It’s a good idea to test it on a small part of the lawn before treating the rest. That’s quick to do, because this stuff works exceptionally fast. You’ll see results in as little as two hours.
It also offers other benefits, including hardening the turf and preventing worm casts. Use a concentration of between 2 and 3 grams per litre of water for this purpose.
If you’ve got any ericaceous plants – azaleas or camellias, for example – iron sulphate is also a great feed and tonic. Just follow the instructions on the back of the tub to get the right concentrations for your plants’ needs.
It won’t, though, kill weeds. If you have a problem with those, you’ll need a separate product. And take care not to get it onto paths, patios or fence panels. It will stain them rust brown.
Pros:
- Large tub for cost-effective treatment
- Will begin to kill moss in as little as two hours
- You can adjust the concentration as required for lighter or heavier areas of growth
Cons:
- You’ll need a separate product if you want to kill weeds as well
- It will leave behind rusty stains if you get it onto fences or paths.
5. Maxicrop Moss Killer and Lawn Tonic
Maxicrop’s formula combines a moss killer with a natural, seaweed-based tonic to green up your lawn. And it works a treat.
It comes in a 2.5 litre bottle, and the liquid is mixed with water before use. The contents will give you enough to cover an area of 166 square metres.
As ever, iron sulphate is the moss killing ingredient. The formula contains 16.4 per cent of the stuff. And it works very fast. The moss will begin to blacken in just a few hours.
That also means it has the same problems with staining as most other moss killers. Keep any children or pets off the grass until the mixture has dried. And take care to avoid getting it onto paths, patios or fences. Once the stains are there, they’re almost impossible to remove.
The seaweed extract here will help promote the growth of strong and healthy new grass. That means bare spots left after you’ve raked out the dead moss will green up much quicker. And used on existing grass, the formula encourages robust roots and lush green blades.
This is designed for use during the warmer weather between May and October. Give the bottle a good shake before you dispense it.
Don’t use it if your lawn is less than six months old, and avoid applying it within three days of mowing. And don’t use it more than twice a year, or within six weeks of a previous application.
Pros:
- Combines moss killer with a natural, seaweed-based lawn tonic
- Works very fast – moss begins to blacken within hours of application
- Liquid formula is easy to use with a watering can or sprayer
Cons:
- Not suitable for use on new lawns, or more often than twice a year
- This is another product that will stain any wooden or paved surfaces it comes into contact with.
6. Miracle-Gro EverGreen Premium-Plus No Rake
This treatment from Miracle-Gro is one of the most expensive on our list. A single 20-kilogram pack will cover up 200 square metres – that’s using the lower end of the recommended dosage range. For optimal results, a pack will cover only 133 square metres.
That means this works out at two to three times the price of other treatments on our list. But you do get one major advantage for this extra expenditure: you won’t have to rake up the dead moss.
That’s because the formula includes bacteria – Baccillus subtilis ssp – which eat the moss. You may need to give them a few weeks to finish the job, but they’re very effective. And you’ll save a lot of hard work raking out the dead stuff.
The bacteria do, however, require the soil to be at least 10 degrees Celsius. If it’s colder, they won’t be active, and your moss will escape unscathed. So this is definitely a treatment to apply during the warmer months.
Alongside the bacteria, there’s a good quality fertiliser with extra magnesium oxide to green the grass. Expect to see a richer colour on your lawn from about a week after application.
And there’s more great news if your lawn buts up against fences, paths or patios. The organic formula doesn’t contain iron sulphate – so you won’t need to worry about any staining. It’s still important to keep children and pets off the grass until it’s dry, though.
Pros:
- No need to rake up dead moss – it will be gobbled up by natural bacteria
- Incorporates a good quality fertiliser, with extra magnesium oxide to promote a verdant lawn
- There’s no iron sulphate in this – so it won’t stain paths, fences or patios
Cons:
- Expensive – and you’ll need to apply 150 grams per square metre for the best results
- Won’t work if the soil temperature falls below 10 degrees Celsius.
7. Pro-Kleen Iron Sulphate (Our Top Pick)
At the other end of the price spectrum comes Pro-Kleen’s Iron Sulphate. One 2.5 kilogram of the powder formula will cover up to 2,500 square metres of lawn. That makes it an exceptionally cost-effective buy. And the tub is easy to reseal, so you’ll be able to keep it in good condition for multiple applications.
The fine-powdered grade means you’re not paying for any water in the formula. And you’ll be able to adjust the coverage depending on how serious your moss problem is.
A solution of 10 grams per litre for every square metre of your lawn will usually give good results. Don’t be tempted to make it too strong, though. That can turn the grass black, although it will recover after a few days.
It can be applied either wet or dry. Diluting it with water, though, will enable it to get to work faster. That will be easy to do with either a watering can or garden sprayer. You’ll be able to see the moss beginning to blacken within just a few hours of application.
As well as killing moss, it will turn your lawn a beautiful deep green and protect it against pests and disease. It can also be used at different concentrations to harden your turf and get rid of worm casts.
Note that this doesn’t contain weedkiller, so you’ll need to use it alongside other products if weeds are a problem. And because it’s pure iron sulphate, it needs to be used with care. If it comes into contact with patios, fences or paths, you will get those rusty stains.
Pros:
- Exceptional value for money
- Blackens moss within just a few hours of application
- Also acts as a lawn tonic, leaving your lawn a lovely deep shade of green
Cons:
- This is pure iron sulphate, so if you need a weedkiller you’ll have to buy that separately
- Take care to keep it away from paving or fences – it will stain if it comes into contact with them.
Buying guide
If you’ve checked out our reviews but aren’t certain which moss killer to buy – read on! We’re going to look at some factors to consider before you make your choice.
When do you want to treat your lawn?
To begin with, consider what time of year you want to treat your lawn. Some moss killers are designed to combat the moss as it grows during the damp autumn months. Others work better when the weather is warmer.
And if you’re using Miracle-Gro’s No Rake formula, the soil temperature will need to be at least 10 degrees Celsius. Any colder than that, and the bacteria won’t be active and your moss won’t be affected.
Make sure you check any other restrictions on when to treat your lawn too. Most moss killers contain strong chemicals, so they’re too harsh for younger grass. As a general rule, it’s a good idea to avoid using them altogether before your lawn is six months old.
And while some treatments can be used repeatedly, others require a gap between applications. This can be several weeks long. Some formulas should only be used twice a year at most.
Does your lawn have other problems?
Is moss the only problem with the quality of your lawn? Or do you also need to give your grass a boost? What about weeds – do you need to remove those too?
Most moss killers will also provide a tonic of some kind to your turf. Pure iron sulphate, also known as ferrous sulphate, is in most cases the ingredient that kills the moss. It will also support healthy lawns, making your grass fresh and green.
If you want to give your lawn extra nutrients, look for formulations that incorporate fertiliser too. Generally speaking, it’s best to use these in spring and summer, when the grass is growing.
Most fertilisers will be a mixture of nitrogen, phosphorous and potassium. Some also contain magnesium oxide for greener grass. And MOOWY’s 2 in 1 uses seaweed extract as a natural source of nutrients.
Some of the products on our list also incorporate weedkiller. That can make your life a lot easier if your lawn has been invaded by dandelions or other weeds. But note that the weedkilling part of the formula can take longer to work than the moss killer.
What hazards do you need to watch out for?
Last but not least, consider any risks from using your moss killer. That’s particularly important if you have pets or children who could come into contact with the toxic chemicals.
In most cases it’s fine for children and animals to return to the lawn after it’s completely dry. But bear in mind that can take several hours.
And think about the position of paths, patios and fences too. If you’re using a moss killer with iron sulphate, it will stain them if it splashes. Think about how you’ll apply it. If it goes on in liquid form, a watering can will give you better control than a garden sprayer.
Ready to say goodbye to moss in your lawn?
That brings us to the end of our round-up of seven of the best lawn moss killers out there right now. We hope it’s helped you decide which one is right for your garden.
Our favourite is Pro-Kleen’s top quality iron sulphate. It offers unbeatable value for money, and it will kill moss fast. And you’ll get a healthier, greener lawn into the bargain.
But if you want to avoid the risk of staining paths and fences, Miracle-Gro’s No Rake formula is a winner. It’s a lot more expensive – but you’ll also be saving yourself a lot of time and effort raking up dead moss. Just make sure you use it when the weather is warm enough for the bacteria to work effectively.
Whichever brand you choose, you can look forward to a lush, moss-free lawn. Just make sure you relax and enjoy it when you’re done!
