The Best Moss Killer For Lawns
Choose the best moss treatment product to remove moss from grass lawns
3 of the best lawn moss killers
Reviewed by the team at DIY Gardening in 2021
Lawn moss isn’t just unsightly, it can grow at an incredible rate and smothers the ground preventing grass from establishing itself.
If you want that perfect green, lush lawn that so many gardeners in the UK dream of, you’ll need to kill any moss that currently exists and also take steps to stop it returning.
Fortunately, the team here at DIY Gardening has tested the most popular moss treatment products and we have extensive experience and knowledge of moss eradication and prevention.
Don’t leave it until it’s too late, remove lawn moss as soon as possible and take one step closer to that perfect British grass lawn.
The growth of lawn moss can be the result of five things:
- Too much shade
- Lack of drainage
- Soil nutrient issues
- Compact soil
- Close mowing
Below you’ll find three products that are very effective at killing lawn moss.
But if you don’t want the lawn moss to grow back, you’ll need to make some changes to your garden.
If your garden is very shaded and you want to grow a lush green grassy lawn, start with our in-depth guide to growing grass seed in shaded gardens.
Product 1) “No Rake” Organic Lawn Moss Killer
This is our favourite lawn moss killer and for good reason; it’s one of only a handful of moss treatment products where you don’t need to rake out the dead moss after applying the product.
This lawn moss killer contains two key ingredients. a moss killer and also a naturally occurring bacteria that consumes the dead moss and thatch that collects at the base of the lawn.
One of the biggest issues with traditional lawn moss killers is how to remove the dead moss and how awful the lawn looks after applying the product. Huge swathes of lawn covered in blackened moss is a far cry from that green lush lawn most of us wish for.
A “No Rake” moss killer works slowly, gradually killing off and consuming the moss. This gives the existing grass time to spread into the free space. You can also help the grass by overseeding as required.
This is also pet and family-friendly, once the product has dried you can let pets and children onto the grass without them coming to harm.
Unlike iron sulphate, this product won’t permanently stain patios, concrete, timber decking, shoes or clothing.
This product is so reliable that it was chosen by the War Graves Commission to treat and remove lawn moss from their graveyards. The commission was concerned about potential damage to the headstones and other features that they needed a slow-acting moss killer that would protect their delicate stoneware while also giving the grass a chance to gradually expand into the space created.
There is a negative aspect to this product: It’s a slow-acting lawn moss killer, you will need to use multiple applications and also periodically overseed the area.
If you’re looking for something that acts quickly, choose a different product where you’ll need to rake out the dead blackened moss and thatch before raking in new grass seed.
If you’re the patient type, you can kill and remove lawn moss whilst also growing grass at the same time.
“No Rake” is our favourite lawn moss killer but it’s not for everyone.
Product 2) Iron Sulphate
Iron sulphate is one of the most widely used products for the eradication and control of lawn moss.
It’s cheap, in fact, it’s one the cheapest lawn moss killers you can buy. You get hundreds of litres of diluted product from just one kilogram of powder and it’s incredibly effective.
You can expect lawn moss to be killed off and blackened in a matter of days with this product.
Dilute and apply with water or sprinkle the powder directly onto the grass and hose in, iron sulphate is versatile and easy to use.
Apply this product in higher doses and it acts as a lawn fertiliser, feeding your grass and encouraging growth.
While iron sulphate is a very effective lawn moss killer, it’s not our favourite product for one simple reason – the damage it can cause to patio slabs, concrete and decking is severe often irreversible.
Iron sulphate eats into patio slabs, marble and concrete where it leaves permanent marks. It also damages timber decking which would need to be sanded and recoated.
Even transfer from pets, wild animals and shoe soles can wreck patios and flooring.
Iron sulphate is also harmful to pets and children who would need to be kept off the grass for at least 24 hours. Apply too much iron sulphate and your grass may turn brown or even black although it should recover.
So, yes, iron sulphate works well at killing lawn moss and it’s made it to number two on our list but it needs to be handled with more care than many other gentler, organic products on the market.
Product 3) Maxicrop Seaweed Base Moss Killer For Lawns
Maxicrop lawn moss killer is a popular product that does three things:
- Kills moss
- Turns the grass greener
- Encourages grass root and blade growth
The product contains iron sulphate at 17% concentration, this is just enough to kill off the moss but not so strong it blackens the grass.
Nitrogen is added at 2% concentration, this fertiliser is used primarily to alter the colour and lushness of the grass. Expect a bright green lawn after applying nitrogen, even in small quantities.
The base ingredient of Maxicrop is seaweed extract, which is a natural fertiliser that encourages both root and blade growth.
Unlike our previous two recommendations, Maxicrop is liquid-based and should be diluted with water. You can apply by watering can or hosepipe mixer.
As this product contains fertiliser, the best time to apply the liquid is in the growing season, so either Spring or Autumn.
How to Stop Lawn Moss Growing Back
Moss grows in lawns for several reasons, no matter how many chemicals you put down or how often you rake out the material, it will come back unless you make changes to your garden.
No matter where your garden is located, what the soil is made from, how much or how little sunlight it gets, you can achieve a lush green moss-free lawn – if you know how.
Read our guide to removing and preventing lawn moss, it goes into more detail about the steps you’ll need to take and goes far beyond just listing the best lawn moss killers.
Products We Think You’ll Like
In addition to our three recommended best lawn moss killers, we think you’ll like these products too:
Soil Home Testing
Soil testing is a key element of professional gardening and by taking action based on the results, your grass and plants will grow stronger, brighter and be more resistant to drought and disease. Check the soil for PH levels, Nitrogen, Potash and Phosphorous.
You can then add fertiliser and nutrients at the correct dose to resolve any issues.
Shade Tolerant Seeds
Grass often struggles to grow in shaded gardens where it leaves patchy areas of bare soil that are perfect for moss to grow and thrive. Shade tolerant grass seeds grow well in shaded areas and limit the amount of moss that can grow in the lawn.
Graminex contains six different shade tolerant grass seed, guaranteeing germination.
Lawn Aeration Shoes
Advertised as a cheap and easy way to aerate the soil under the lawn, these shoes have mixed reviews on Amazon and other online retailers, so we tested them. Lawn aeration is a great way to loosen up a compacted ground, but do lawn shoes work?
Head over to our blog and see what we think of lawn shoes and a few alternatives.
Our Favorite Mower
This is our favourite mower for large areas; it’s petrol-powered, comes with a mulching bag and most importantly has six cutting heights from 2.5cm up to 7.5cm. If you have lots of moss in your lawn, letting it grow tall can help to suppress the moss.
This self-propelled petrol mower makes cutting grass to any height easy with reduced effort.
Electric Lawn Rake
Electric scarifiers are perfect for raking out dead moss, old grass blades and thatch from your lawn. While a manual rake is suitable for a small garden, this product makes light work of scarifying larger lawns. Remove the moss and free up space for the grass.
This Black & Decker electric rake has plenty of positive reviews on Amazon – it’s a great product.
General Lawn Fertiliser
Westland’s Growmore Garden Fertiliser is a general purpose fertiliser with 7% Nitrogen, 7% Phosphorous and 7% Potassium. This product is perfect for preparing the soil near tree and plant roots where there is competition for both water and nutrients.
The low-release granules are perfect for preparing soil prior to lawn sowing or growing plants.
The lawn Guide Book
Our favourite book: The Lawn Guide by Sharples and Hayman is a great read, learn how to prepare a garden for laying turf or seed. Where this book truly excels is in its lawn maintenance advice and tips which are extremely detailed and second to none.
Want to know how to grown the perfect lawn in any condition? This is the the book for you.
Manual Lawn Rake
This manual lawn rake has been specifically created for lawn scarifying. The hooks on each blade are designed to lift out moss, dead grass and thatch from the base of the lawn. Used regularly, lawn grass will be able to thrive in the space created by this scarifier.
Made in Germany, this is a sturdy and well-built lawn rake built for one thing – lawn scarifying.
Lawn Moss Killer FAQs
What Causes Moss to Grow in Grass?
Moss may grow in gardens that are dark, shaded, receive limited natural light, are waterlogged, have drainage issues, compacted soil or have such poor soil nutrient quality that grass is unable to establish itself. Moss will often take advantage of any bare patches that form in thin, sparse grass cover and spread from there.
Does Moss Growth Kill Lawn Grass?
Lawn moss grows in the bare soil created by grass that has failed to establish itself. The moss doesn’t kill the grass but fills in the gaps and slowly spreads throughout the lawn. Excessive moss cover indicates an issue with the quality of the lawn and grass growing conditions.
Can I Remove Lawn Moss Without Using Harmful Chemicals?
Regular dethatching, raking and overseeding can help. For lawns with considerable moss infestations, consider using a product which contains bacteria that consumes the moss.
Can Lawn Moss Growth be Prevented?
There are many steps you can take to prevent lawn moss, many go hand-in-hand with improving the grass quality and coverage:
- Aerate the soil
- Increase the natural light reaching the lawn
- Use shade-tolerant grass seed to improve grass cover.
- Regularly dethatch, scarify and rake the lawn.
- Improve the quality of the nutrients in the soil to promote grass growth.
What is the Best Chemical to Treat Lawn Moss?
Iron Sulphate is the most commonly used product to treat lawn moss. Be aware that it may stain patios and paths and pets should be kept off the grass for 24 hours.
Explore More of our Lawn Care Guides Below:
All LAWN GUIDES
See all of lawn guides published here at DIY gardening, from how to grow grass in shade to dealing with pet urine damage, wear and tear and moss control. Start Here
HOW TO GROW GRASS IN SHADED GARDENS
Read our in-depth guide to successfully growing a lawn in a shaded garden where grass often struggles to grow. Start Here