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This article was last updated on August 7th, 2021 at 6:32 am

We’ve all had a moss problem in our home at some point. It could be the lawn, decking, the roof, or tarmac and block paving. Moss can actually be quite slippery and therefore dangerous, let alone ugly and unsightly when growth occurs in unwanted spaces.

Pinning down a single cause of moss is very difficult, some would say almost impossible as there are a lot of factors at play. So what can be done about this problem? Actually, quite a lot. The UK market is flooded with products designed to tackle moss, whether it is on a hard surface like a garden path or driveway, or on a lawn. You can start lawn a lawn scarifier and then move onto a lawn weed and feed. The moss that grows on your lawn is a separate problem entirely and requiring a different type of product to get rid of and help your grass grow back to its previously healthy state.

Moss growing on your lawn could be caused by any number of things. If your grass gets too dried out by drought it causes moss to grow, but if you over do it with the hosepipe and cause your lawn to be waterlogged, guess what? Yes, that’s right. Moss growth. It could also be caused with problems in the soil such as it being overly acidic.

When it appears on patios, it can be because that area is in the shade a lot, or affected by certain weather conditions. If you get actual weed growth as well, you might do better to consider a weed killer for block paving specifically.

Not all products are as effective as they should be though, and we thought it would be helpful to take the best sellers and test/review them for you to find the best moss killer available in the UK. A moss killer should work effectively in a reasonable time frame, be well priced, biodegradable, safe for use with children or pets, and easy to apply. We have reviewed products that can be used on patios, block paving, wood, and any hard surfaces in general specific so that we are sure you’ll find something that will help you out with your own moss problem. If you’re looking for a lawn moss killer please head to the appropriate page now.

Comparison table: Best moss killer for patio, block paving, and steps [Summer 2021]

ProductWhat We ThinkPrice

Wet & Forget - Moss Mould Lichen & Algae Remover (5 Litre)

  • Non-caustic, Non-acidic, Contains no bleach
  • Mix 1 part Wet & Forget with 5 parts water in a garden sprayer then 'Wet & Forget'...
  • One 5L bottle makes 30L of product
  • It's easy, no scrubbing
  • Just Wet the Area & Forget it

Jarder Spray & Leave 4 x 5 Litre Concentrate Cleaner


  • Excellent value for money on bulk purchase
  • Spray and leave rather than clean
  • 240m2 of coverage


  • Takes a few days to work
  • More of a fungal killer than cleaner

Simply Spray & Walk Away Concentrate Patio - Fencing - Decking - Mould Algae & Moss Killer

  • Pro-Kleen Simply Spray Liquid concentrate
  • Non-acidic, Contains no bleach
  • This professional patio sealant from Pro-Kleen leaves Indian Sandstone
  • Provides your flooring with a waterproof seal to protect from weathering and staining...
  • How to use PatioSeal: Ensure all surfaces are clean and free from any dirt...

Patio Magic Patio Cleaner 5L

  • Ready to use hard surface cleaner that kills and controls green mould...
  • Battery operated Power Sprayer for easy application; 4x duracell AA batteries included...
  • Just spray and leave; no scrubbing
  • For use on outdoor paved areas
  • Visible results in 2-4 days

If your moss problem is on your driveway, fence, or just about any other hard surface, Pro-kleen’s simply spray &walk away moss killer should be right at the top of your shopping list. It is easy to mix, all you do is use one part concentrate to four parts water and you’re good to go. Then use any garden sprayer to apply it to the moss infected surface and wait for it to start working. Just like the name says ‘simply spray & walk away”.

We tested this on some old wooden garden furniture whose legs had been colonised by green moss recently while it was stored in a shaded corner of a garden. For the first couple of days, there wasn’t any visible change and I was ready to write it off as an overrated product, but then on the third day we started to see something, and it just got better and better, day by day, until the moss was completely gone. We also tested it on some wooden fencing and this time the results were obvious on the second day. I have to say I was impressed.

There is a knack to getting the most out of products like this and it all comes down to timing when you apply it to the infected area. For more details please read our buyer’s guide at the bottom of this page.

Usually, the moss and weed killing products that work the best are quite strongly bleach based, but this is non bleach, non-caustic, non-acidic, and is completely biodegradable with a neutral PH balance. You’ll have to keep your kids and the dog away from the sprayed area for a little while, but once it’s dried they are safe to play around there.

A five litre bottle of this moss killer concentrate costs around 15 pounds, and once mixed with water will give you five times that. What’s more you don’t have to worry about using it all before the expiry date as there isn’t one. You can have this sat in your shed or garage for as long as you like, ready to use again.

Pro-kleen have come up trumps here with this fantastic moss and algae killer and I have no reservations about recommending it to anyone who has a moss problem on their path, decking, fencing, etc. A must buy.

Not interested in products that you have to mix and measure? Don’t own a garden sprayer?

With the Patio Magic ready to use spray, everything is already set up for you, leaving the only task of actually spraying the moss killer onto the affected surface. This solution comes pre-mixed so there’s no measuring to worry about, and attached onto the 5 litre bottle is a small, battery operated sprayer (four Duracell AA batteries are included). This really is a handy product for people on the go who don’t have time, or just simply don’t want to spend time, going through the whole process of measuring, mixing, pouring into a sprayer, etc.

A 5 litre bottle of this ready to spray moss killer will set you back around 20 pounds and will allow you to treat an area of about 35 square metres. There is a concentrate version of the same moss killer available which costs about 4 pounds less, but there is no sprayer included and you will have to go through the mixing process yourself.

So, does it work?

The answer is definitely yes. I’m always wary of products that offer things like free sprayers and such as they are often gimmicks used to hide an inferior product. Not so, in this case. We sprayed an area of patio that has some moss and lichens, but unfortunately a rain storm came out of nowhere and soaked the sprayed area= so we had to wait and try again when it was dry. This time though we got luckier with the weather, and saw that the moss killer was indeed doing its job after a couple of days.

Like the simple spray & walk away moss killer, your kids and pets are free to play in the sprayed area once it has completely dried. However, this product can be harmful to your plants so be careful when spraying.

This is a moss killer that offers a ready to go, easy to use product to those who desire that kind of thing and it works well if used correctly. At its current price point it isn’t as cost effective as buying a concentrate but I guess that’s the cost of convenience.

If you’re using this to sort out the patio, I highly recommend sealing afterwards, so take a look for a good patio sealer here to complete the job and a full guide on restoring your patio.

Patio Magic Patio Cleaner 2.5L Refill

3. Wet & Forget - Moss Mould Lichen & Algae Remover (5 Litre)

Wet & Forget claims to be a tried and tested product and used by theme parks and other public places to kill moss and keep it away from various hard surfaces. Well, not one for believing in advertising spiel, I decided to put it to the test on some concrete steps to see for myself if it lived up to the company’s claims.

This moss killer comes as a concentrate in a 5 litre bottle for around 30 pounds in the UK. The recommended dilution is one part concentrate to one part water, and after a little bit of calculation I worked out that a five litre bottle should cover an area of about 200 square metres or so.

After mixing the moss killer and spraying the steps, we waited to see results. Knowing that patience is key with these products we weren’t surprised to see nothing had really happened after a day, then two, then three, but after day four we were ready to condemn Wet & Forget.

Then it happened, on day six the moss began to die, and die quickly. That was over 2 weeks ago and I’m happy to say that all the moss has gone and there are no signs of it coming back any time soon, fingers crossed. This stuff really works, it just takes a while longer than most so be patient.

The makers claim that once it has dried into a surface, it will continue to work on killing moss and will be reactivated every time it rains in the future. I can’t attest to that to be true as it hasn’t been long enough since we sprayed it to say, but after looking online at customer feedback, it seems that it is true.

This moss killer matches the simple spray & walk away product in safety design as it too is non-caustic, non bleach, neutrally PH balanced, biodegradable, and safe for your family.

All in all, a great moss killer for steps, patio, block paving etc. at a reasonable price. Just expect to wait a while to see results.

If you’re looking for a moss killer that works on patios and the like, you are spoilt for choice these days. Jarder’s spray & leave is yet another fantastic product for just such a problem and very fairly priced too.

This super concentrate’s recommended dilution is one part moss killer to 5 parts water, but Jarder says this is only a general guideline and you are free to add more or less water depending on the severity of the moss problem.

We stuck with the maker’s advice for our test and chose a particularly mossy bit of decking as our ‘canvas’. Using a pressure sprayer, we put a decent coat of the soapy like substance on half of the decking so that we could check back in a few days to see how it compared to the untreated half.

Jarder claims results in 2-3 days and for it to keep on fighting moss for 6 months after. I can’t comment on the 6 months part of the claims, but after three days there was a noticeable difference between the two different parts of our test area. A couple of days after that and it was even more clear which side had been treated with the spray & leave moss killer.

It was also blindingly obvious that we hadn’t been so careful while spraying too as a couple of nearby plants had copped a coating and were starting to wilt. Even though most of these products are biodegradable, non-bleach, etc. these days, they are still not good for your plants, so be a little more careful than we were when spraying.

Spray & leave can be used on almost any kind of hard surface from fencing, to roof tiles, and even PVC window frames, and does an excellent job of getting rid of moss and algae. This is another product I can wholeheartedly recommend.

Moss Killer Buyer’s Guide

Still feeling a little lost about what product to buy and how to use it for best results?
Don’t worry, this short moss killer buyer’s guide will give you all the information you need to know. Let’s begin.

Granules, concentrate, or ready to use?

On the other hand, if your problem is on your patio stones or garden path, you are probably going to be better off using a liquid form of moss killer. These usually come in concentrate form and need to be diluted with water before use, but there are some that come pre-mixed and ready to use. Concentrates offer you more control over the strength of the solution but they do require a little more preparation. Ready to use products are more convenient but you are stuck with the solution as is.

When to apply moss killer?

Concentrates work best when they are applied to a dry surface and are allowed to dry in for a few days. If you experience heavy rain within 48 hours of you spraying, it might have a negative effect on the performance of the moss killer. Granules work differently and the optimum time to use them is in spring when the temperature rises above 10 degrees Celsius and there are frequent rain showers.

Be patient

Moss killers take time to work, so please be patient. Granules that are used on lawns are particularly slow acting, and this causes some people to add more, thinking that they aren’t working. This actually causes damage to the grass and makes the problem worse.
Concentrates work faster so you should see the difference within 3-7 days in most cases.

Be careful and follow the instructions

If you are spraying concentrate on an area that is in close proximity to your plants, you have to be very careful or you might kill them. It might be a good idea to temporarily cover them with something while you spray just in case. Also, make sure that the area is fully dried out before letting any pets or kids play in there as there will still be toxins around if it is still damp. Remember to always wear gloves when working with any chemicals and don’t enter the house with the same shoes that you were wearing while applying the moss killer or you could damage your floors or carpets.

If you follow our advice set out here in this buyer’s guide, and choose one of the excellent products we have tested and reviewed for you, we are sure that any problems that you have with moss or algae will soon be a thing of the past. If you are looking for a good pressure sprayer to apply a moss killer concentrate we have a page full of reviews of such products so why not pop over and take a look?

Our aim is to take the guesswork out of buying gardening products so that every customer, is a happy customer

About Terry Smith

I’m Terry Smith from, a professional landscape designer, hobbyist gardener, and barbecue fanatic with 20 years experience building and restoring. So as you go through my site you'll watch me document some of the professional garden installs I make as well as the major projects I take on at home. While sharing those experiences and guiding you, I'll be recommending some great tools I use to enable this along the way so you can really buy in confidence.

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