5 Ways To Remove Green Algae From Metal Garden Furniture

By   | Last Updated :   August 24, 2021 | Filed In :   DIY & How To

Are you having problems with algae growing on your metal furniture? You’re not alone.

Green patches of slimy algae don’t look attractive on garden furniture. Fortunately, you can take care of the problem with some water, a variety of solutions and elbow grease.

remove algae metal furniture

Slimy algae can easily be cleaned off garden furniture. Credit: Pxhere

Now you might be wondering if it’s even worth cleaning your furniture since it’s still raining outside. Well, let’s take a look at what algae is and what it does to your furniture.

What is algae and what does it do to your furniture?

Algae is a large group of organisms that thrive in warm, damp, shady environments.  They propagate by sending microscopic spores into the air. Many people believe that leaving your furniture out in very cold weather or placing it in the sun in summer will kill algae. Unfortunately, this is not true.

All that will happen is the growth of the algae will slow until conditions become favourable again. Algae is very slippery which can make chairs and tables hazardous for use. It will also ruin your clothes when you sit on the affected furniture.

Algae can quickly overtake any surface and when left untreated can cause rust on wrought iron furniture which in turn weakens the structure making it dangerous to use.  It is best to remove algae as soon as you notice it. Here are some tips to do just that.

How to remove algae from metal garden furniture

It’s very easy to remove algae from your furniture but you’ll have to put in some work. If you catch it early on, it will mean less work so I’ll recommend that course of action, but if it’s already got bad you can use the following to get the algae back under control:

1. Warm soapy water

Sometimes all you need to get rid of algae is some warm soapy water and elbow grease. Simply add a little dishwashing soap to some warm water, mix until lather forms on the water and then use a sponge or brush to wash away any algae on your furniture.

When you’re done, give your furniture a good rinse with clean water and leave it out in the sun to dry.

2. Vinegar homemade algae removal solution

Vinegar is a very versatile substance that can be used for many different purposes, including getting rid of algae.

Simply mix 1 part vinegar with 1 part water and spray it on the algae. Leave it on for about 10 to 15 minutes before scrubbing it with a sponge or soft brush to get the algae off and then rinse with water.

white vinegar water homemade cleaner

Credit: Shutterstock

If you have particularly stubborn algae, try mixing two parts vinegar with three heaped tablespoons of baking soda and 1 part water. This solution is more potent and should kill the algae faster while loosening it from the metal. Leave it on for 10 minutes after applying before you start the scrubbing process. Rinse well after and make sure you got all the algae stains.

After rinsing, you can leave your furniture in the sun to dry.

Tip: Remember not to use any hard metal brushes or a scourer since they’ll damage the underlying metal. These damaged spots tend to rust since you’ve removed the protective galvanised counting of the metal.

3. Pressure washing

Pressure washing is another chemical-free way to get rid of algae.

power washing garden furniture

Credit: Shutterstock

Just make sure you keep a safe distance to not damage your furniture in the process. Once done, make sure you dry your furniture properly to avoid rust.

4. Bleach

If you don’t mind harsh solutions on your furniture, you can kill the algae with some bleach. The most common oxygen-based bleach used for this purpose contains hydrogen peroxide. The bleach will kill and lift the algae from your furniture making it very easy to clean.

5 Ways To Remove Green Algae From Metal Garden Furniture 1

Hydrogen peroxide is an effective algae remover. Photo by Towfiqu Barbhuiya on Unsplash

To create a bleach solution simply mix a ¾ cup of bleach with a spoonful of laundry detergent in a bucket of warm water. Make sure your furniture is far away from any plants and materials that will get damaged by the bleach.

Apply a generous amount of the solution to the affected areas and let it sit for 5 minutes before scrubbing it off. Make sure to use gloves to avoid getting burned by the bleach. Once you’re done thoroughly rinse the furniture and let it dry in the sun.

5. Commercial products

If you don’t trust any of the homemade solutions, or they just don’t seem to work for you, you can go the commercial way.  There are a lot of products out there specifically made to remove algae from garden furniture. All you have to do is choose one for your metal furniture and follow the instructions on the packaging.

Before jumping in and covering your furniture in any solution, first test out the product in an inconspicuous area. Sometimes a solution may react with the material your furniture is made of and cause damage. If this happens, don’t use it on the rest of your furniture.

It’s also always a good idea to use environmentally friendly products if possible.

How to prevent future algae growth

If you understand what causes algae to grow, you’re more able to stop it from happening. Algae need a moist, warm environment with lots of shade to grow. This type of environment is easy to create if you let leaf litter build up on your furniture.

To prevent algae growth, regularly sweep any leaf litter off your furniture.

woman gardener sweeping the garden

Credit: Shutterstock

If your furniture is in an area with dense trees and deep shade, you’ll have to make an effort to at least wipe your furniture once or twice a month.  Damp gardens with lots of shade and a swimming pool are often perfect for algae growth. So are gardens in areas with a warm, humid climate.  You’ll have to put in a little more effort to keep your furniture algae-free, but in the long run, it will be worth it.

You can also create covers for your furniture or even store them in a storage room or in the garage if you know it’s going to be miserable outside. This way your furniture will be protected against weather damage and excess moisture which will inhibit or even prevent algae growth.


What naturally kills algae?

If you don’t want to use any harsh chemicals, try a vinegar and baking soda solution. Vinegar and baking soda will both kill and loosen the algae making it much easier to remove without damaging your furniture further. You can also just use some warm water and scrubbing power or even pressure washing to remove any algae, but it will be harder and the algae might return faster.

How long does it take for vinegar to kill algae?

10 to 15 minutes. Vinegar usually works quite quickly. All you have to do is let it sit for about 10 to 15 minutes before scrubbing off the algae. If there’s any left, repeat the process.

How do you clean metal garden furniture?

Metal furniture should be cleaned with a soft sponge or cloth to prevent scratching the finish. Abrasive scrubbers and harsh detergents may scrub away and dissolve the galvanised finish on your furniture leading to rust in the future.

Read more: How To Clean Garden Furniture Cushions


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