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This article was last updated on August 7th, 2021 at 8:51 am

Solutions to age old problems

Patios, garden paths, decking, and stepping stones are all very common features in gardens across the UK, and for good reason. There is nothing quite like sitting out there on a summer’s day, relaxing on your garden furniture, while the barbecue cooks a spot of lunch.

Now, I know I’m being idealistic here and the reality is somewhat different. Usually, the truth is, you go outside after months of winter weather to see your patio has been slowly colonised by algae, lichens, and moss, leaving an ugly patchy green layer covering your normally beautiful paving or the deck is slippery and desperately needs a quality deck cleaner! This layer isn’t just an eyesore, it can also be potentially dangerous as it is usually very slippery and you don’t want your kids running around on it. It’s not just the decking either, this will work on wooden table and chair sets too.

There is also the problem of mould growing on your garden furniture, especially if it has been stored in a dark and damp place like a shed for a while.
So what to do about these problems? Well, it depends on the severity of the growth and a few other factors.

Some people like to use a pressure washer to blast out moss from between paving stones, and this can be quite effective, especially on wooden garden furniture. However it is also very messy and some of the excess water could get trapped in certain areas and make the problem worse.
You could also scrub the algae, moss, etc. off by hand using a hard brush of some kind but this is quite labour intensive.

Then there are specialised chemicals that are designed to make the removal of algae and other similar growths much easier especially patio cleaners which can have ultra stubborn growths. It is these products that we will be reviewing today to find the best algae, moss and mould remover.

Best Algae, Moss, and Mould remover Reviews


Comparison table: What’s the best algae, mould, & moss remover? (November 2020 Updated Review)

ProductWhat We ThinkPrice

HG Mould Remover Foam Spray

  • Immediately removes mould from damp places and especially on silicone seals
  • Can be used inside and outside
  • Foam formula stays in place longer making it more effective
  • Suitable for cleaning tile and plaster walls
  • Also suitable for marble and other natural stone as well as other surfaces...

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

ULTIMA-PLUS XP Patio Cleaner 5 Litres Super Concentrate

  • Super Concentrate: the most powerful and concentrated patio cleaner on the market...
  • Amazing dilution rate: our super concentrated formula means you only need 1L of solution per 9L of water...
  • Suitable for all hard surfaces: Perfect for use on patios
  • 100% safe: biodegradable. PH8
  • prevents regrowth: penetrates your outdoor surfaces creating an invisible barrier which will help to prevent re-growth for up to...

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

Our top pick has to be the 5 litre version of Patio Magic’s patio cleaner. 
We chose the 5 litre bottle in particular because it comes with its own battery operated spray gun. Just pop in the 4 AA batteries that come with the patio cleaner and you’re ready to go attack that mouldy growth.

The spray gun is a compact plastic device that can be held comfortably in one hand while you carry the patio cleaner solution in the other, and because it is battery operated, you don’t have to keep stopping to pump up the pressure. While the spray gun is not the highest quality available, it will continue to do its job properly if you treat right and look after it, just like any garden tool. There is a concentrate version of this patio cleaner available if you prefer to dilute it yourself, but I actually like the convenience of this one being premixed and ready to go, as it saves on both time and guesswork.

It is easy to use too. Just spray it on the hard surface where the problem is and leave it to dry. It is important that the area that you’re working on is dry, without any puddles or areas of trapped water, and also that it is not expected to rain for the next 24 hours at least. For best results you should spray on a dry sunny day and this should let you see a noticeable improvement within 4 days or less and over a longer period of time (weeks) it can work wonders so some patience is required.

Patio Magic’s patio cleaner is completely biodegradable and won’t leave any residue or stains behind. This also means that once it has dried, it poses absolutely no risk to your children or family pets, and they are free to play in the sprayed area. Just make sure that it has completely dried up before though and this usually takes about 5-6 hours depending on conditions.

After treating the desired area, the algae removing effects should last about 6 months but this could be less if the area is constantly in the shade or poor drainage keeps the area damp. I would spray again after a few months anyway just to make sure. I’ve always thought it’s better to be proactive when dealing with moss and mould.

Now for the downsides. It should be pretty obvious that spraying this algae remover should be done very carefully as to not get it on your flower beds and foliage a sit will probably damage them. I accidentally over a sprayed on one area and it did kill the flowers next to it.

Also, with some particularly thick lichens and black spots it struggled but that is nearly always the case and jobs like that usually need a stronger more industrial strength cleaner. 
You will also still have to do a little scrubbing with a brush, no matter what Patio Magic claim, but this algae, moss and mould remover does make it much easier to get the growth off without too much elbow grease. Don’t forget to use a good patio sealer straight after to stop dirt and new growth for as long as possible!

Patio Magic Patio Cleaner 2.5L Refill

HG Mould remover is a versatile product that can be applied onto range of surfaces from plaster walls to garden statues, and from bathroom tiles to hot tubs.
 While primarily used for indoor surfaces, it can also work well on things you find in the garden. Particularly swimming pools, garage floors and surfaces and planters. It is important to note, however, that this is only for removing mould and not algae, moss, or lichens.

As a mould remover though, this product is excellent and also easy to apply. All I needed to do was spray the foam onto the mouldy area in my bathroom and leave it for half an hour. Then I came back and wiped the area with a sponge and the mould had all but disappeared. There was a damp patch on the wall where I had sprayed that had me worried, but this dried out without leaving any stain or mark within the day.

I think the reason this mould remover works so well is that it is a foam and sits/sticks to the mould while it removes it. You can actually see and hear it working the instant you spray it on (or maybe that was just my overactive imagination haha) and it also has the added benefit of not running down instantly from the sprayed area onto more sensitive materials such as fabrics. There will still be some run off though once the foam dissolves into liquid so be careful with that.

As with everything, HG mould remover foam spray does have its faults. Most noticeably is the strong smell that reminded me of when someone has been overzealous with chlorine in a swimming pool. For this reason it is a very good idea to have the room properly ventilated when using it and also wear some breathing protection to keep it out of your lungs. Also, leftover liquid can block up the nozzle so you will probably have to clean it out with warm water before each use.

Apart from these small flaws, HG mould remover is a good product that does what it claims and is particularly impressive when tackling black mould from ceramics and stone. It would be a good product for cleaning a hot tub or similar.

For just over 30 quid you get 4×5 litre bottles of Jarder Spray & leave concentrate cleaner. With each 5 litre bottle able to produce 30 litres of solution once diluted, that’s good value for money.
 Jarder Spray & leave is meant for outdoor use and will help you get rid of all the usual culprits such as algae, moss, and mould from fencing, decking, patios, and just about every other garden surface you can think of. 
Caravans have become increasingly popular in recent years, so it is good to know that you can use this product on them as well as boats, and even on uPVC windows, the most common type of window in the UK.

I tested this on my garden path which had a fairly thick growth covering it after a harsh North East English winter and I was happy with the results. I followed the manufacturer’s instructions to the letter, making sure that I sprayed the path in the late afternoon on a bright and dry day using a pump action garden sprayer and left it to do its job.

I was expecting results after 2-3 days, and while there was some improvement, it wasn’t as good as I had hoped. However, after another couple of days I could really see the difference and after another week or so it had really done a good job.

I was worried for a while after spraying as a whitish colour to my path not too long after spraying, but after looking online I realised this was normal and this disappeared before too long.

While this algae, moss and mould remover is harmful to plants and flowers, and also fish, once dried out it is safe for your dog and kids to play in the area. Depending on the concentration level that you mix it at, this product could also damage your grass, so that is something to keep in mind.

Talking of concentration levels, one of the nice things about having an algae and moss remover in concentrate form is that you can tailor it to suit your needs. I liked the ready to use Patio magic patio cleaner for convenience and ease of use, but it did struggle with lichens. With this product you can simply dilute it less, or not at all, to tackle those hard to shift growths. Just be careful with it.

One thing I will say about this product though is that while it did a good job of shifting the algae, it did take a while to work the way Ai thought it would and after a month or two I started to see signs of it growing back, so more applications would be needed to keep your patio or path algae free all year round. Still, with 4×5 lites of concentrate, you would have more than enough to do that.

The biggest selling point of Ultima-Plus XP is that it is not only a very affective algae, moss and mould remover, but also that it offers incredible value for money. 
It is not called super concentrate for nothing and the high strength formula only requires one part concentrate to be mixed with 9 parts water. This means that you can get 95 litres of working solution out of a single 5 litre bottle of concentrate. For easier jobs such as very light algae or moss, you could even dilute it further.

Like most algae, moss and mould removers, you are advised to apply it during spells of dry weather, but not during the middle of the day as intense sunshine can evaporate much of the product leaving it much less effective.

Following these instructions, I used the Ultima-plus on some fencing that had some quite thick growth on it. The bottom of the fencing spends a lot of time in the shade so the algae was particularly bad there. After spraying, I left it to go to work and waited to see the results and was not disappointed.

After a week, the solution had done a great job of breaking down the growth and I only needed to brush the remnants off, which was an easy job as there wasn’t much there, and the fence looked as good as new. There was no discolouring or staining on the wood either.
 This was done a few months ago, and to this day the fence is still growth free and looking great after I used a decent fence stain, so this says something about the long lasting protective effects of the solution.

The Ultima-Plus XP patio cleaner can be used on just about any hard outdoor surface from bricks, wood, and stones, to roof tiles, and because it isn’t a bleach based solution, it won’t stain or damage your garden statues or patio floors. It is also biodegradable and non-caustic so it won’t corrode any of your more delicate surfaces.

The downside of this product is much the same as many others of its type, namely the strong odour so please wear a mask when using this product and if you’re using inside, make sure the area is well ventilated.

Algae, Moss, and Mould Remover Buyer’s Guide

Before deciding on which algae, moss, or mould remover to buy, please spend a minute or two looking at our short buyers guide. Here’s a few things to consider-

Ready to use or concentrate.

These products usually come in either ready to use form or concentrate. If you are a person who enjoys convenience, then I would suggest going for a ready to use solution that is already mixed for you. 
Concentrates are a little messier and need you to measure out amounts and mix yourself, but they offer better value for money and also allow you to dilute the solution differently to suit various jobs, which can come in handy.

Liquid solution or Foam.

Liquid solutions, either ready to use or concentrate are more common, but there are foam products out there, particularly with mould removers.
Foams can be less messy than liquids and the foam will stay in contact with the mould for longer which could help with removing it faster.

Liquids tend to be cheaper and you get more for your money. This could be important if you have to treat a large area.


Some algae, moss or mould removers contain strong bleaches, giving them a not so pleasant odour that can cause headaches. These products can also stain and discolour surfaces if you are not careful. However, these products are often the most affective at shifting growth, but not always so. If you’re worried about damaging your surfaces, go for a bleach free solution.

Know what your product is meant for.
Some products are all-in-one and can remove algae, moss, mould, and more, but others are more specialised and only mean to tackle a particular problem. Make sure you read up on a product before you buy it as it may not be the best option for your needs.

Follow the instructions.

To get the most out of any algae, moss, or mould remover, you need to follow the manufacturer’s instructions to the letter. Failure to do so will more than likely give you less dramatic results or even stop the product working.
In general, you want to spray when the weather is bright and dry. Spray in the late afternoon as direct or strong sunlight can cause the solution to evaporate. 
If it rains within a few hours of applying the solution, you will probably have to wait for the area to dry and then spray again.

Also, give the product time to work. Often the advertisers will tell you a product shows results after 2-3 days, but in my experience it usually takes longer to see a noticeable difference.

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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