How to remove algae from garden furniture — 4 ways to get it looking like new, ready for spring

As the sun finally begins to peek through, many of us are emerging into our gardens for the first time after a long and wet winter, only to find that algae has taken hold of our garden furniture. But before you start thinking about buying new, learn how to remove algae from garden furniture, and you might find it looks like new on its own.

As brighter days spent outside beckon, now is an apt time to learn how to clean garden furniture to prepare your garden for cloudless skies and long days lounging outside.

‘Cleaning your garden furniture and removing any algae is important, as not only will it help to maintain the appearance of your furniture, but it'll also help it to last longer,’ says Reilly Gray, co-founder of outdoor living specialist, Suns Lifestyle.

Algae is a common problem on garden furniture and particularly thrives in dark, damp, wet conditions – which this winter has provided plenty of.

‘Wooden garden furniture suffers from algae problems the most, however, it's also common on metal and plastic garden furniture too,’ says Lee Trethewey, interiors expert at Sustainable Furniture. While not furniture, wooden garden fences are also often prone to algae outbreaks, so knowing how to remove algae from a fence is also an invaluable tool when priming your garden for sunnier months.

‘Algae thrives in damp and shady areas, leaving green or black stains on wood, metal, plastic and rattan surfaces alike,’ adds Reilly. ‘The key to removing it is to use the right cleaning methods for the material you're cleaning to avoid any damage.’

It’s important to figure out the best practice for your specific garden furniture material to avoid causing any long-term damage to your outdoor furniture when you’re sprucing up for spring. Follow these experts’ tips to see which is the best method for your situation.

1. Scrub with washing up liquid

If your algae problem is only small, or you are cautious about harming your delicate outdoor furniture, using washing up liquid is a gentle and cost-effective way to deal with the problem. To do this, Lee advises: ‘Mix some washing up liquid with warm water. Use a soft brush to scrub the furniture gently – you could also use a sponge here. Rinse off.’

If this doesn’t work, and some algae persists, Lee recommends using specialist wood cleaner in place of the washing up liquid, which should be stronger on the algae while designed to protect the furniture.

‘Make sure that any shop-bought product you buy is suitable for your specific type of outdoor furniture. Some may not be suitable for use on treated wood, so this is something to look out for,’ advises Lee.

As a starting point, consider Ronseal's garden cleaner, which is available at B&Q. It is suitable to use on hard wood and soft wood and will tackle algae growth.

2. Use a white vinegar solution

Using a white vinegar solution is a slightly more potent way to remove algae from garden furniture. To do this, Thomas Roe, Outdoor Building Specialist at Garden Buildings Direct recommends: ‘mix one part white vinegar to two parts water to remove algae from wooden garden structures.'

'Start first by brushing off algae with a soft bristled brush or a broom. Don’t use one with hard bristles - this could damage the wood.

'Apply the white vinegar and water solution, leave for 15 minutes before rinsing off. For stubborn stains, reapply,' Thomas adds.

‘Many prefer the white vinegar method as white vinegar can be stronger than washing up liquid, however white vinegar could stain certain types of wood,’ warns Lee. It’s therefore worth patch testing the vinegar solution before covering wooden furniture with vinegar, just in case it causes any damage.

3. Wipe with diluted bleach

Not a method for wooden furniture, but if you have metal or plastic garden furniture that’s fallen victim to algae, brushing it with a bleach solution can be an effective way to remove the green residue.

‘For metal and plastic furniture, a diluted bleach solution of one part bleach to ten parts water can work really well,’ says Reilly. ‘Apply it with a sponge or spray bottle, allow it to sit for a few minutes before scrubbing gently with a brush or sponge.’

It’s important to remember to thoroughly rinse your furniture after using this method to remove any chemical residue, as leftover bleach can also be harmful for the surrounding environment.

4. Use a pressure washer

If you have fairly resilient garden furniture and the algae is proving particularly stubborn, using a pressure washer is an efficient way to remove algae from your garden surfaces. Using the best pressure washer is one of the fastest ways to solve any unwanted algae problems.

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How to prevent algae on garden furniture

When your garden furniture isn’t in use, there are a number of measures you can take to prevent future algae build up.

‘The best method to keep algae away is to clean your outdoor furniture regularly and remove any algae as soon as you notice it,’ says Lee. ‘This will stop the problem from becoming too extensive, and potentially damaging your wooden furniture in the long run.’

‘By getting into a good routine of regularly checking and cleaning your furniture and using furniture covers during the wetter seasons, you'll be able to reduce algae growth and ensure your furniture is always kept at its best,’ agrees Reilly. ‘Regularly applying protective treatments will also help to ensure your furniture stays clean and in top condition for years to come.’

There you have it – happy spring cleaning!