Last updated on March 25th, 2024
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Just recently, I have been on a testing spree to see which patio cleaners really are the best, and I’ve tested different patio cleaners on different surfaces, from paving slabs at a local garden centre to york stone in my own back garden and even on my own resin drive.
I even went a step further to test them on my family’s driveways and patios to better understand how well they work on various surfaces and different types of lichens, moss and algae etc.
My Best Patio Cleaner review explains what to look for in a patio cleaner and evaluates the best cleaners on the market. I look at the pros and cons of each cleaner I review, such as does it need brushing in? Does the surface need watering down first and rinsing afterwards? As well as discussing what situations they’re best and safe for.
My Buyer’s Guide further down looks at the few essential issues that you need to consider when making your decision
BEST PICK
RUNNER UP – BIODEGRADABLE
Have you got a tarmac drive that has seen better days? Check out this guide on the best tarmac restorers to bring it back to life
Top 7 Patio Cleaner Reviews
1. Smartseal 5L Patio Clean Xtreme
BEST PICK
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I will get this out of the way first, I don’t know what they have put in it but the results are nothing short of amazing. When I first applied it I could see the results almost instantly. I even tried it on a small area of my resin driveway and the image below is after only around 4-5 minutes. You can see that the left side looks almost new.
I have also treated my whole resin driveway with this cleaner and it looks new now, as you can see in the pictures shown below.
I usually do the resin drive with my Karcher K5 Pressure washer, this is something I have also reviewed here but using this patio cleaner was much easier and faster.
Below are a couple of pictures I took before testing this product on my york stone patio, the second one being only 2 hours later after I had rinsed it off with the hose pipe and let it dry.
Further down I have more images of the excellent results after using it on blackspot on paving slabs that hadn’t been cleaned in years!
So, the first step in using the Smartseal cleaner is to decide how you want to dilute it. Five litres of the concentrated solution treats approximately 40m2 of the patio when it has been diluted. Now this means it is fairly expensive when you consider the coverage and price per 5 litres of concentrate, however, the results it gives, especially on black lichen, are incredible.
I think it’s worth the price when you consider other patio cleaners which say they cover more square metres. However, what they actually don’t say, is that by the time you have applied it 2-3 times to get a surface clean (for more soiled surfaces), I have probably paid a similar amount per square metre cleaned.
In other words, I paid more for this patio cleaner but I only needed to apply it once, or twice on very stubborn black lichen and blackspot.
How to use it
So first I mixed 1 part water and 1 part concentrate (1:1 solution) using a 1 litre jug. If you are trying to get rid of very stubborn blackspot, then you can use the solution at full strength so it isn’t mixed with water. Personally, I didn’t do this, I just applied it twice over a 4 hour period and it did just the job on the worst areas, and these were actually paving slabs at a local garden centre.
Something to note, I always apply patio cleaner with a garden sprayer, I have even reviewed some here. It’s the most effective way of applying it compared to using a watering can (which is the second option) because they can be so wasteful and you won’t achieve the same coverage that you get using a sprayer.
If you don’t have a sprayer, I would strongly recommend investing in one and you can get them cheap from most gardens centres or even from Amazon. If it was me, I would avoid using a watering can.
Next, I watered the area down to make sure it was damp, you may want to sweep any dirt or debris from the area first though.
With the area damp, I then started to spray the area with a good covering of Extreme patio cleaner solution I have mixed 1:1.
After spraying the area I then used a stiff brush to work the cleaner into the surface. In the image below I’m actually working it into paving slabs and I followed the same process for my york stone patio and some other concrete areas.
Once I brushed the solution in, I left the treated area for around 1-2 hours, I think in the example below, I left it for one and half hours but the longer the better has been my experience.
Next, I simply washed it down with a hosepipe. The images below are before and after and I would also like to point out that these paving stones haven’t been cleaned in around 20 years.
The Smartseal Patio Clean Xtreme is a professional-grade cleaning product that will bring your patio up like new. This patio cleaner is a highly concentrated cleaner that works on natural stone, paving slabs, crazy paving and paving block floors.
You can use a pressure washer afterwards to clean the surface off but I have not even needed to do that. I simply hosed it down to rinse off any chemicals.
I have also used this on my wall tiles underneath my bay window and it came up really well (as shown below), and again, they have not have been cleaned for many many years.
Now for the downsides
First off, it’s a little more work to apply compared to my Runner-up, the Ultima plus XP (which is also more environmentally friendly). You need to brush the cleaner into the area for the best results and rinse it off with clean water afterwards.
Not a big deal but with Ultima plus XP, you simply spray the surface and walk away, job done, no rinsing. However, you don’t see results in a couple of hours with the Ultima XP. With this cleaner it’s almost instant, I literally saw results in minutes, not days.
Also, be aware that the Smartseal cleaner isn’t friendly to vegetation and you need to be careful too. Because this cleaner contains chlorine, it smells rather strongly of bleach and will take out the colour of any clothing it splashes on. If some of the cleaner gets on your plants, rinse them down quickly and thoroughly. As always, wear gloves and avoid contact with your skin.
Pros
- Professional grade cleaning product for a deep clean.
- Cleans most hard surfaces including sandstone and brick surfaces so all your patio surfaces will look better.
- Spray on, brush in, wait, rinse off. The process is quick and easy.
- No pressure washing needed, saving time and effort.
- 5-litre container covers 40m2 at 1:1 dilution.
- Cleans most of what gets on your patio – black spot, algae, lichens, moss and dirt.
Cons
- Harmful to vegetation and takes the colour out of clothing.
- Contains chlorine; smells strongly.
- Expensive compared to some other patio cleaners.
Our recommendation
If you don’t like using chemicals or have an area next to a water source, for example, a pond or stream, you can’t use this, although choosing not to use chemicals is always a personal choice.
However, for everyone else, I think this is the best patio cleaner currently available. I can’t stress how impressed I have been with the Smartseal Patio cleaner and the results it gives.
It may be more expensive than some of the alternatives but none are as effective at cleaning hard surfaces. And none even come close to how quickly you can have your patio looking like new. I really couldn’t believe how fast the surfaces I tested this on came up clean and other family members were equally as impressed.
Now it didn’t have any negative effects when I used it on my resin drive but I would test it out on a small part first because it doesn’t mention using it for resin driveways on the container. Overall though, it’s got to be one of the best patio cleaners currently available.
2. ULTIMA-PLUS XP Patio Cleaner
RUNNER UP
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The Ultima-Plus XP Moss, Mould & Algae Killer is a highly concentrated cleaner that gets rid of all the unwanted algae, moss, mould and even kill moss. The only downside to this, when compared to the Xtreme patio cleaner I have tested above, is that it takes around 5-7 days to see the results. I will start by saying, it works great on green mould and algae, however, blackspot or lichens, not so much.
I actually tested this against Smartseal Xtreme patio cleaner on my york stone patio which was full of green mould and algae but not black spot or lichen. Both products worked well but the Xtreme patio cleaner had one half of the patio like new in a couple of hours but this Ultima plus XP took around 5 days to see good results. It did work and the patio looks great, it just took a little longer.
However it’s more affordable, will often go further because it makes 50 litres, is easier to apply and you don’t need to brush it in or rinse off afterwards.
A 5-litre container covers an area of around 400m2 of patio surface but you get this using a sprayer like I did. I wouldn’t advise using a watering can because it wastes too much.
You get a minimum of 50 litres at the recommended dilution of 9:1 which is what I mixed it at for my testing.
Below you can see the results against spraying Ultima Plus XP patio cleaner on my York stone patio. The patio was full of green algae and after only 5 days you can see it’s completely gone. I did not have to brush it in, I’ve not even rinsed it off and it’s not even been raining between treating it and taking the second picture. Yet the results are good and you can see a big difference, there is simply no green algae now.
Obviously, the higher the concentration, the more effective the solution will be at cleaning. So maybe for more soiled surfaces you might need to have it more concentrated, but for me this wasn’t the case.
What I do like about the ULTIMA-PLUS XP solution is that it contains no acids or bleach but still remains effective in exterminating extra growth. It is biodegradable and once it has dried, you can let your family and pets play out on the patio. It is recommended that you use gloves if you have very sensitive skin but I would strongly advise that you wear gloves anyway as I do.
So as mentioned, once you have mixed it you simply spray on it, ideally with a sprayer as I am doing above, and that’s it. Simply let it dry, walk away and wait to see the results.
So the results were good on green mould on algae so I tried it on black mould on paving slabs that were heavily soiled.
Now I did not see any effects the first couple of days, in fact, I nearly wrote it off as a waste of money for black mould but then around 5 days later I started to see results and within 7-10 days the areas I had treated was looking noticeably better but not amazing.
I have since treated it again to see if it improves or perhaps it just needs more time to work so I will report back soon!
I wanted to do further testing on this product, so I also sprayed my brother’s patio. The first picture is before any of the cleaning solution was added, and you can see he has lots of moss between the flags, green algae over much of the patio and black mould too.
After a couple of days, to which you can see in the picture below, that the moss between the flags is dead and the green algae is gone. The black mould is much better although not completely gone.
This again reminds me that this ULTIMA-PLUS XP Patio Cleaner works very well on green algae and moss. No rinsing or brushing in either, just applied with a sprayer and walked away. Overall great results.
Pros
- Simply apply and walk away and see results in as little as 3 days.
- Can be used on all hard surfaces outside your home.
- Various dilution ratios for different levels of griminess.
- Biodegradable, thus environmentally safe.
- Includes no bleach or caustic substances that can affect surfaces.
- Safe for pets and children once dried.
Cons
- May take 2 or 3 applications for the most stubborn stains.
Our recommendation
The Ultima-Plus XP Moss, Mould & Algae Killer is cheaper than most of the other products featured in my review, yet it is certainly one of the best patio cleaners I have seen for cleaning green mould and algae. I like that it’s is biodegradable, non-caustic and therefore safe to use all around. Pets and children can be let loose onto treated areas once the floor is dry, which on a summers day would be within an hour.
The Ultima-Plus XP Moss, Mould & Algae Killer is a safer choice than some other patio cleaners (including my best pick) if you have pets and young children who won’t stay out of the garden for long enough when you’re trying to make your patio look more respectable. Overall it did a good job, it just took a while to see the results from my effort but this was also the case with all ‘apply and walk away’ type patio cleaners including Algon which I review next.
Read next: Best patio sealers for protecting your patio, paths and driveways
Need to give your patio a refresh and apply new grout? Check out my guide where I review the best patio grout compounds
3. Algon Patio Cleaner
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I have been using Algon for years and we use it at my family’s garden centre every year on the gravel paths to control moss and algae and it works amazingly well.
I have also have been using it on my resin drive for a few years because I didn’t want to risk using a strong chemical based cleaner on it, just for the fact I wasn’t sure if it could damage the resin. I have since tried the two previous cleaners on it and it has turned out fine.
You can see below where I have only sprayed algon to the right-hand side of my resin driveway and how clean it looks compared to the left-hand side which I did not spray with algon. These results were noticeable after only 5 days.
With the garden centre being open to the public and they get a lot of children and pets coming in, we only ever use cleaners that are marked as safe for pets and children.
Algon is an organic cleaner that is also very affordable and I have always experienced good results with it. It usually starts to show results in around 7 days similar to Ultima Plus XP my runner-up patio cleaner.
Our recommendation
If you have an issue with moss and algae, I can confirm that this patio cleaner works well and will kill the moss and algae. What I also like about Algon is you can use it near ponds, you obviously need to make sure you avoid any run off into ponds, however, if you do get a little run off, it won’t harm the wildlife in the pond. Something else I have noticed about this product is that the treated areas stay moss and algae free for around 9 months, sometimes as long as 12 months so it has long-lasting effects.
4. Wet & Forget – Moss Mould Lichen & Algae Remover
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The Wet & Forget Moss Mould Lichen & Algae Remover is an alternative to our Best Pick because it needs no hard work and takes care of moss, along with the usual mould and algae. All you need to do is dilute 1 part concentrate with 5 parts water, spray it and forget about it. On days that you are away from the property, this is especially useful. Why? This is because the detergent embeds itself in the patio and is reactivated whenever it rains.
This slow method of killing off mould and algae is simple and attainable. This patio cleaner is not acidic or caustic. With no traces of bleach, you don’t have to breathe in toxic fumes or worry about the environment and wildlife. This cleaner is biodegradable and has a PH of 7 which is stable enough not to harm your skin or the patio surface.
The 5-litre container treats around 100-300m2 of patio surface, depending on the volume and age of the stains you have. The detergent is not only for patios and you can also use it on paths, patios, wooden decking, garden furniture, planters and caravans.
Pros
- Easy to use: mix, apply and leave.
- Biodegradable without caustic elements so your family, pets and patio are safe.
- Needs little or no maintenance after the first application.
- Saves energy because manual scrubbing is not needed.
Cons
- Not fast-acting.
Our recommendation
The Wet & Forget Moss Mould Lichen & Algae Remover is a great alternative to our ‘Best Pick’. It’s easy to use because this is another ‘mix, apply and walk away’ cleaner that requires no scrubbing. We like that it continues working for up to 12 months to keep the moss and algae away. Though you may need to apply it a second time on really badly stained surfaces.
The Wet & Forget Mould Lichen & Algae Remover is a great choice if cleaning the stains and mould on the patio is not your favourite garden task. It’s a little more expensive (at the time of writing) than our Best Pick.
5. Jarder Concentrate Spray & Leave Cleaner
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The 5 Litre Concentrate Jarder Spray & Leave Cleaner is another spray and walk away patio cleaner. Expect to see results in only 2-3 days depending on the level of growth of moss, mould, algae and lichen you have. This concentrated patio cleaner needs no scrubbing or invasive abrasive tools to pry the growth out of the patio.
Another good feature of this product is that it contains no bleach. The patio cleaner is neither acidic nor caustic so your surface tops are protected from damage, as is your skin and clothing. 
It is also friendly to the environment due to its biodegradable characteristics. Too many chemicals can unbalance the soil and prevent further growth in future if you get them onto your prized plants. Just because it is biodegradable does not mean that it is not effective.
With the right dilution ratio of water and cleaner concentrate, you can cover up to 240m2 of ground. Remember that you have to let the areas dry before letting pets or children play around on the patio. It is an important safety precaution.
Pros
- Minimum of 30 litres of patio cleaner from 5 litres of concentrate which is enough to treat a huge 240m2.
- Suitable for UPVC windows, sheds, fences, patios, paths and more.
- Has no bleach so appropriate for all surfaces.
- Needs little attention because you spray it and leave it.
- Needs no manual scrubbing.
Cons
- Not always effective on stubborn stains.
Our recommendation
The Jarder Spray & Leave Cleaner is environmentally friendly and yields quick results. The patio cleaner is not very strong in that it will be able to remove the stains right away but changes occur in a few days. You may need to apply it a couple of times before you see good results.
This is another ‘mix, apply and walk away’ biodegradable patio cleaner for those environmentally conscious people with other things to do than scrub the patio. However, it’s best on lightly stained patios and other hard surfaces.
6. Pro-Kleen Mould, Algae & Moss Remover
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The PROKLEEN Mould Algae & Moss Killer is another patio cleaner that you can depend on. Employing the spray and leave it method means little maintenance is required to get rid of your algae and moss and prevent their regrowth.
Diluted in the recommended ratio of 1:4, the patio cleaner covers a wide area with 25 litres of solution. If you have a small patio, this patio cleaner will last a long while which gives you value for money.
This product contains no bleach and therefore it is friendly to your skin. It is also not acidic so any protective polishes on your surfaces hold up. Once it is applied and the cleaner dries, the biodegradable material is safe to be around pets and humans. You can use this cleaner on other hard surfaces, even your roof can benefit from a cleaning.
Pros
- Cleans other hard surfaces including fences, drives, patios, walls, furniture and caravans.
- Biodegradable so environmentally friendly.
- Contains no bleach or high acidic levels that can damage surfaces.
- Minimal manual labour because you just spray it and let it dry.
- Doesn’t have a shelf life so you can store and use it for longer.
Cons
- Need to scrub areas with tough stains.
Our recommendation
The PROKLEEN Mould Algae & Moss Killer is affordable and biodegradable. It has problems with accumulated years of algae and mould but handles thin layers of growth well. It works great on green algae but struggles with black algae and you will need some manual scrubbing to remove that.
If your main patio problem is a shallow growth of green algae, this is the cleaner that provides an environmentally friendly solution for you.
7. Patio Magic! Green Mould and Algae Killer Liquid Concentrate Patio Cleaner
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The Patio Magic! Green Mould and Algae Killer Liquid Concentrate work like most of the products in this category. The only difference is how much patio cleaner you can get from one bottle. In areas where there is prevalent growth, the diluting ratio of this cleaner is 1 part concentrate to 4 parts water which is fairly strong. In cases of light growth, you can dilute the concentrate up to 9 times. This is a lifesaver when you have a large patio with light algae growth to treat.
This 5-litre patio cleaner is eco-friendly and can be absorbed into the soil without any harm. When diluted, one bottle covers an area of 170m2. All you need to do is spray the solution and leave it to dry. Once it has dried your patio will be available to your whole family again. You can apply a few coatings if you see any regrowth on your patio.
As with many other patio cleaners, this Patio Magic! one can be used on other outdoor hard surfaces. Make sure that you follow the instructions so that the patio cleaner works effectively.
Pros
- Spray area and walk away – couldn’t be easier to use.
- Range of dilution ratios for your particular patio problem.
- Contains no bleach or acids that can damage surfaces.
- Biodegradable which reduces soil and water pollution.
- Antibacterial characteristics raising the quality of your environment.
Cons
- Control of lichens can take from 2 weeks to 6 months
Our recommendation
The Patio Magic! Green Mould and Algae Killer Liquid Concentrate is affordable and does the job well. This patio cleaner works faster than the Wet & Forget – Moss Mould Lichen & Algae Remover giving you results in just a few days.
The Patio Magic! Green Mould and Algae Killer Liquid Concentrate is perfect for you if you need your patio cleaned quickly because it works faster than most other patio cleaners. Well, except for on lichens.
Our Buyer’s Guide
Buying the right patio detergent requires some consideration because you are buying chemicals that affect your garden as well as possibly your family and pets. Some chemicals may be appropriate for one kind of surface but completely damaging to another surface. In the marketplace, you will find varied brands with varying concentrations that you can use. This Buyer’s Guide highlights the factors to consider.
The surface you are cleaning
What kind of surface does your patio have? Is it limestone, concrete, block paving, Indian stone or wooden decking? Different surfaces react to different chemicals in various ways. Patio cleaners that are heavy in bleach might damage surfaces like wood and strip off the protective coating.
Patio detergents with sodium hydroxide are usually too strong for most uncoated surfaces. Look at your surface and select a patio cleaner with a suitable pH value. Some chemicals may be harmful to your skin too, especially if it is sensitive. The good news is that we did find patio cleaners that were suitable for all surfaces which makes it much easier to choose just the right patio cleaner.
Cleaning procedure
How intense is the dirt or greenery that you want to be rid of? Some patio cleaners can produce immediate results while others take a bit longer. We review several ‘mix, spray and walk away’ brands that are the easiest to use and require the least effort. These ones don’t need scrubbing, you let the chemicals work unless you have very stubborn stains or a lot of moss or lichen. Depending on how fast you want to get your surfaces clean and back into use, select a patio cleaner that can produce results in the time that you need.
Area of coverage
The area you want to clean, the length of time since you last cleaned it and the amount of dirt matter. Some patio cleaners are slightly denser than others. The higher the concentration, the smaller the area of coverage. When you dilute the concentrated cleaner, it goes further but it’s not as strong. We found most 5-litre cleaning concentrates could clean around 400 square meters.
Abrasive substances
Some patio cleaners are acidic or feature caustic substances, such as our Best Pick. These are intended for deep cleaning and may harm the smooth textures of some materials. Some even bleach the area making it look different to the surrounding patio space. If you have sensitive woods or other surface materials, make sure you buy a patio cleaner that does not feature these elements. We suggest only using a deep patio cleaner when you really have to.
One of our patio cleaners isn’t a concentrated detergent at all. It’s a hovercraft-type brush that hooks up to a pressure washer. The force of the jet spray loosens dirt and unwanted plants from the patio surface and washes them away. This is a great alternative if you don’t want to use any chemicals on your patio surface.
Environmentally friendly
We need to take care of our environment so that our environment takes care of us. By using biodegradable patio cleaners, you effectively clean your patio without too much harm to your garden and your loved ones. Because these cleaners are not acidic you will find them more merciful for some soil types.
Look at the information provided by the manufacturer to confirm if the product is environmentally friendly. But bear in mind that stubborn stains or lichen may need more than one application of these cleaners to remove them and prevent them.
Final Conclusion
There’s a patio cleaner in our review for you, no matter how bad your patio looks at the moment. You may want to just get rid of the unsightly green and black stuff growing all over it, or perhaps you want to clean the bricks or paving stones as well. And you don’t have to use chemical cleaners for this, even if they’re biodegradable and don’t harm the environment or your surrounding garden. We review an attachment for a pressure washer that’s especially designed to clean a patio.
The Best Pick in our Best Patio Cleaner review is the Smartseal 5L Patio Clean Xtreme. This is a patio cleaner that cleans deep and stubborn stains and all kinds of unwanted plants. However, it does contain bleach and can harm your skin and discolour your clothes.
One of our favourite alternatives to using a patio cleaner is the non-detergent patio cleaner, the Karcher T 7 Plus Patio Cleaner. This is a hovercraft-like attachment for a Karcher pressure washer that is designed to efficiently clean patios. It has a rotating power spray jet that is much faster than a lance-type pressure washer attachments.
Our Best Pick of biodegradable patio cleaners is the Ultima-Plus XP Moss, Mould & Algae Killer. This is a non-caustic cleaner that works on most hard surfaces outside your home as well as the patio.
Last update on 2025-07-03 / Affiliate links / Images from Amazon Product Advertising API
