Gardening expert explains why algae grows on your patio and how to remove it

A square concrete patio paver (stepping stone) with moss covering it surrounded by mulch.
Algae can be a warning sign of poor drainage in your garden -Credit:Getty


As the weather begins to improve, people will be heading out to their gardens to get their patios and grass ready for the summer.

Many people will have abandoned their back gardens during the colder months due to rain, snow, wind and more adverse weather. But if you have noticed your once-glistening slabs are now covered in green algae then you should be getting to work cleaning it.

While algae is not dangerous necessarily, it can be unappealing to the eye and make surfaces very slippy, reports the Mirror. It can also be a sign of poor drainage in your garden which leads to stagnant water and rotting fences.

Luckily, there is a way to banish this slimy stuff, according to a gardening expert. Guy Barter, chief horticulture adviser for the Royal Horticultural Society, blames the vast growth of algae on the weather - as we've witnessed record levels of rain and even flooding in the last few months.

Speaking to the Sun, Guy said: "Algae particularly favours the prolonged drizzle we've been having. As we expect winters to become milder due to climate change, it's likely we could see more of this type of algae growing."

The expert added that algae tends to form in shadier places in the garden that have poor drainage and a "lack of air flow".

Old red bricks walkway with some green moss.
Algae particularly favours the prolonged drizzle we've been having -Credit:Getty

He said: "It's a tough old thing and if there is an opportunity to grow, it will find it."

You can get rid of the algae with a pressure washer but these are expensive. You can pick up the Karcher Pressure Washer from Amazon for £69.99 but if you can't afford that then don't stress - there is a cheaper option.

Gardening fans have been raving about a £6.99 holy grail that does the job just as well. One user who was in need of a quick fix took to the Mrs Hinch Army Cleaning Tips Facebook page to ask for help.

The woman wrote: "I've used Wet and Forget and Wickes' own version successfully on my white render but it's not worked on my greened decking and nor has pressure washing."

Several members of the page straight away said that the woman should grab a bottle of the Spear and Jackson's Spray & Leave as many branded it 'brilliant'.

Another wrote: "Yes, I used this on my wood decking..."

You can grab this cheap cleaner from Home Bargains for just £6.99.