How to Kill Moss on Driveways Without Using Dangerous Bleach

Whether driveways are made up of asphalt, concrete, or beautifully designed block pavers, at some point they are going to attract moss. This is because all the joints between blocks or cracks in tarmac are perfectly protected, damp areas for moss to grow.

Many people use dangerous bleach to kill moss on their driveway. This is not only extremely bad for the environment but not always 100% successful not to mention the smell!

What Can I Use to Kill Moss on My Driveway?

There are many chemical moss killers on the market and all have a reasonable affect on moss.

The success or lack of success is usually the application of the moss killer. Most moss killers are mixed with water and sprayed onto the moss and this is where the problem lays. The moss does not receive enough of the chemical to kill it properly.

An Asphalt Tarmac Driveway sidewalk Covered with Sodium Percarbonate
An Asphalt/Tarmac Driveway Covered with Sodium Percarbonate

Sodium Percarbonate is the most effective moss killer you will come across for one very good reason. The application of the granules is obviously simple but, when the granules react with water they create a mass of bubbly liquid.

The liquid soaks the moss and works it’s way down into all the cracks and crevices killing the moss rhizoids (roots) and the spores (the reproductive part of moss) as it goes, creating 100% Kill of the moss and preventing the moss regrowing.

killing moss on driveways sidewalks and pavements
Sodium percarbonate on Asphalt/Tarmac reacting with water, creating oxygen killing moss

­The Easiest and Quickest Way to Kill Moss on Your Driveway or Sidewalk

­Sodium percarbonate granules need water to react. This can be fresh water from a hosepipe or rain. If no rain is imminent, dampen down the area with water and then spread the granules using a gloved hand at a rate of about 2oz/50grams per square meter.

If I know rain is definitely going to fall I will go out and spread the granules shortly before the rain. It doesn’t matter which method you use.

Once the water and sodium percarbonate meet, the granules will dissolve and work their magic, creating oxygen and lots of it! There is nothing more to do.

Don’t worry about plants or nearby grass they will be unaffected by sodium percarbonate.

What is the White Residue Left After a Sodium Percarbonate Application?

­Sometimes when sodium percarbonate has finished reacting with water, usually about 40 minutes, there is a white chalky residue left behind.

There is no need to worry this is just soda ash a byproduct of the reaction and will be washed away by the next rain shower or if no rain is imminent you can rinse off with a hose the next day.

You can buy sodium percarbonate easily from

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  1. could you tell me please, can I use this stuff to kill algae on indian sandstone?