Many of you have known and probably used some form of oxygen bleach/sodium percarbonate as a stain remover on your clothes and furnishings. It is little known that it can be used with great effect in the garden as a moss and algae killer, with the added benefit of being a very efficient eco cleaner.
The proper name for oxygen bleach is sodium percarbonate. Despite it’s technical sounding name, it is an environmentally safe product.
Sodium percarbonate is NOT a chlorine bleach, Chlorine bleaches are corrosive and toxic, please do not use chlorine bleaches in your garden!
How to Kill Moss using Sodium Percarbonate
Moss and Algae attach themselves to surfaces like wood and tarmac by tiny hair-like structures called rhizoids. Sodium percarbonate breaks these rhizoids, effectively cutting off the moss and algae’s support system.
Try not to use a pressure washer to remove moss, this just increases the chance of the moss returning.
One of the greatest benefits of using sodium percarbonate to kill moss, is that it is brilliant at killing the spores that allow moss to reproduce, this helps prevent the moss returning.
Buying Sodium Percarbonate.
Sodium percarbonate comes in the form of free flowing tiny granules and is classed as technical grade 100% pure. It is usually shipped in polyurethane bags or a plastic tub. The label is often generic as the granules have so many uses but mostly sold as home brewing bottle sanitiser or clothes washing stain remover. Sodium percarbonate is mostly sold by independent suppliers through Ebay or Amazon and a few online trade suppliers.back to menu ↑
What’s the Best Way to Kill Moss on Tarmac and Roofs?
The sodium percarbonate granules need water to react and create the oxygen. The easiest and most effective way is to spray the area to be treated with water and then sprinkle the granules over the whole area. You will see the granules immediately start to bubble as the oxygen is released and that’s all you have to do!
TIP: If you are sure that a good amount of rain is going to fall within the next few hours, then sprinkle the granules straight onto the moss and let the rain do the rest. This is especially effective if you are treating moss on roofs. I have treated many roofs with sodium percarbonate using this method.back to menu ↑
Have You Got Weeds and Moss?
If your driveway is covered in moss and weeds, have a look at Neudorff Weed Killer. This product contains Pelargonic acid which is found naturally in plants, pelargonic acid kills both moss and weeds.
Although Neudorff produce separate weed killer and moss killer bottles, they are essentially the same product. You can read more about it Here
Other Uses for Sodium Percarbonate.
Organic matter like algae is broken down by the oxygen which makes sodium percarbonate an effective and inexpensive method for cleaning indoors and out. Some of the best ways to use it are:
- Cleaning wooden garden furniture
- Algae killer on patios
- Kills algae in water features Further Reading
- Cleaning Decks
- Lifting Bird muck
- Killing Moss and Green Algae on and between Block Paving
- Killing Moss on Tarmac, Drives, Patios and Paths
- Moss Killer for Tiled and wooden Roofs
- Sanitising pots
- Stain remover
- Kills Moss on Tennis Courts
- Cleans Artificial surfaces
- Tile Grout Cleaning
- Worktops (Except solid wood worktops, as they have usually been treated with Danish oil)
- Put half a teaspoon in a tea or coffee stained cup and fill with warm water, leave then rinse. The cup will be as clean as the day you bought it.
- Do not use on pure or untreated wool, silk or leather.
What else can Oxygen Bleach be used for?
We always have a bag of Sodium Percarbonate handy, It can be used together with other detergents and improves their performance. We use a scoop in our laundry, a scoop in our bucket when we mop the floors. It is great for deodorising bins, septic tanks, cleaning dishwashers, washing machines, de-staining tea and coffee cups/pots and general sterilising.
Oxygen Bleach in action.
When spraying, Sodium Percarbonate needs to be mixed with warm water. This creates a bubbly reaction so if you are using it in a sprayer you need to be careful not to mix up too much at one time. Spray all over and leave for 10 to 15 minutes, you will see the oxygen lifting the dirt, use a brush for very soiled areas and then simply rinse with clean water
- Sodium Percarbonate can be used with other detergents
- Use a capful in your washing machine to keep your whites whiter and coloureds brighter!
- Mix 30 grams with 1 litre of warm water
- Spread by a gloved hand or scoop, use approximately 50 grams per square metre.
- Sometimes the mix leaves white mineral deposits on the cleaned area. This will disappear after rain or an extra rinse, it is not permanent!
- Always try a small test patch first.
- One of the advantages of this great natural product is that it does not affect plants or grass as a commercial chemical would. If you over spray near these you have no need to worry!
How do Alternative Moss and Algae Killers Compare?
There is no doubt that the main brands do a good job at killing algae. However, they don’t all kill moss, so beware.
Many of the cleaner concentrates are sold in bulk packs. One I found was selling 4 bottles of concentrate for around £30, if this was mixed as suggested, it would cover a massive 960 sqm, that’s a lot of mixing and spraying!
All that said, these main stream products are fantastically good at their job, so I have included them in this post.
If you are not used to working out square areas and the amount of solution to cover that area, these off the shelve products, can involve a bit of brain work to ensure enough of the mix goes on to kill the moss or algae.
The other factor I find frustrating, is the lack of coverage information. Some manufacturers quote maximum coverage areas.This is achieved by mixing more water with the concentrate provided, therefore giving a weaker solution.
You may feel like you are getting more for your money but in reality its a bit like washing some greasy plates with only a tiny squirt of washing up liquid.back to menu ↑
How to Work Out Patio Cleaner Mix and Area Coverage
I will try to explain this as simply as I can
You will often see in the marketing blurb “One 5 Litre bottle of concentrate makes a minimum of 30 litres of solution ” .This means the bottle you buy is mixed 1:5. So 1 bottle of bought concentrate will be mixed with 25 litres of water.
1:5 means 5 Litres of water x 5 = 25L of water + 1 Litre of concentrate = 30 Litres of Solution. (so there we are, as clear as mud!)
or “Mix 1 Litre of Concentrate with 4 Litres of water” .
1:4 means 4 Litres of water x 5 (because there is 5L of concentrate) = 20L of water + 1 Litre of concentrate = 25 Litres of solution.
The Best Alternatives for Killing Moss and Algae
Patio Magic 2.5 L
- Max Coverage 75m2
- Will Kill Algae
- Danger to Aquatics
- Cant use if Rain is Imminent
- Will Prevent Regrowth
- Approx cost £0.24p per Sqm
Wet And Forget 2L
- Max Coverage 120sqm
- Will Kill Algae
- Can’t Use if Rain is Imminent
- Danger to Aquatics
- Approx Cost £0.18 per Sqm
Jarder Spray and Leave
- Max Coverage 240sqm
- Will Kill Moss and Algae
- A Danger to Aquatics
- Can’t use if Rain is Imminent
- Approx Cost £0.05 per Sqm
- Prevents Regrowth
Pro Kleen Patio and Fence Cleaner
- Max Coverage 200 Sqm
- Kills Algae
- A Danger to Aquatics
- Cant Use if Rain is Imminent
- Helps Prevent Regrowth
- Approx Cost £0.06 per Sqm