How do I clean mould off my garden furniture cushions?

You lift the cushion off your favourite outdoor chair after a rainy week, and there it is: a constellation of grey-green speckles, that faint damp-cellar smell, and a sinking feeling that you might need to buy replacements. Before you reach for the bin bag, take a breath. Mould on garden cushions is stubborn, yes, but it’s rarely permanent. In most cases, you can remove it with things you already have in your kitchen cupboard, a bit of patience, and one sunny afternoon.

What makes mould so persistent is that it’s a living organism, not a stain. It sends tiny root-like threads into fabric fibres, which is why a quick wipe often just smears the surface and leaves the problem to return a fortnight later. The trick is to kill the spores, lift the discolouration, and then dry the cushion thoroughly enough that it can’t come back. Get those three steps right, and your cushions will look and smell fresh again. Miss the last one, and you’ll be doing the whole job again next month.

Below, I’ll walk you through what actually works, based on years of dealing with exactly this problem on my own patio furniture — including the mistakes that cost me a set of cushions early on.

Start by Assessing the Damage (and the Fabric)

Not every mouldy cushion deserves the same treatment. Before you mix anything, take two minutes to check what you’re dealing with. Flip the cushion over, look at the seams, and press the fabric where the mould is worst. If the cover feels crunchy or the foam inside has gone black, the mould has penetrated the filling and no surface treatment will save it — you’re better off replacing the foam block and keeping the cover if it’s removable.

Next, identify the fabric type, because this determines how aggressive you can be:

• Removable, machine-washable covers: the easiest case. Check the care label for a temperature guide and wash separately from other laundry.
• Non-removable covers on synthetic fabric: treat in place with a gentle solution and a soft brush.
• Cotton or linen blends: more prone to staining and shrinkage, so use cooler water and avoid scrubbing hard.
• Waterproof or coated fabrics: never scrub with abrasives — you’ll strip the coating and make the cushion permanently absorbent.

A real example: a neighbour of mine once attacked a coated outdoor cushion with a stiff wire brush and neat bleach. The mould vanished, but so did the water-repellent finish. Within a week, the cushion soaked up a rain shower like a sponge and the mould returned worse than before. Gentler is genuinely faster in the long run.

The Cleaning Method That Actually Works

Here’s the routine I’ve settled on after trying the harsh chemical route and regretting it. It uses white vinegar, bicarbonate of soda, and a little washing-up liquid — nothing exotic, nothing that will wreck your patio plants when you rinse it off.

1. Take the cushions outside. Never clean mould indoors. Disturbing it releases spores into the air, and you don’t want those settling into soft furnishings or your lungs.
2. Brush off the loose spores first. Use a soft-bristled brush outdoors, wearing an old mask if you’re sensitive. This stops you from grinding spores deeper into the weave.
3. Mix a solution: roughly one part white vinegar to three parts cool water, plus a teaspoon of washing-up liquid per litre. Vinegar disrupts the mould’s growth without bleaching your fabric.
4. Apply and let it sit. Spray or sponge the solution on, then wait ten to fifteen minutes. This dwell time is what kills the spores — skipping it is the single most common mistake.
5. Work the fabric gently. Use a soft brush or microfibre cloth in circular motions. For stubborn patches, sprinkle bicarbonate of soda directly onto the damp area and work it in with your fingertips; it lifts discolouration without abrasion.
6. Rinse thoroughly. A garden hose on a low setting works well. Leftover residue attracts dirt and can irritate skin.

For heavier infestations, you can substitute the vinegar solution with a diluted oxygen-based bleach (the kind used for laundry stain removal), which is colour-safe on most fabrics. Avoid chlorine bleach on anything coloured or coated.

One practical case worth mentioning: a reader once told me she’d been scrubbing her cushions every spring for three years without success. The problem wasn’t her cleaning method — it was that she stored them stacked in a plastic box over winter. The trapped moisture meant mould was regrowing from day one each season. Fixing her storage solved a problem that cleaning alone never could.

Drying and Preventing the Return

Killing mould is half the job. Drying is the other half, and it’s where most people slip up.

After rinsing, stand the cushions upright on their edges rather than laying them flat. This lets air circulate through both faces and stops water pooling in the seams. On a warm, breezy day, most cushions dry in three to five hours. If the weather turns, bring them indoors and point a fan at them — a damp cushion left overnight is a mould nursery.

A few habits that keep mould away for good:

• Store cushions indoors or in a ventilated storage box during wet spells. Sealed plastic containers without airflow are the enemy.
• Bring them in before rain if you can, rather than relying on covers that trap condensation underneath.
• Stand them on edge after every wash, not flat on a table.
• Air them monthly during humid seasons, even if they look clean.

If your cushions live outside year-round, consider a breathable cover rather than a waterproof one — the waterproof type often traps moisture inside, which is exactly what mould wants.

Quick Comparison: Which Approach for Which Situation?

FAQ

Can I use bleach on coloured garden cushions?

Chlorine bleach will lift mould fast, but it will also fade most colours and can weaken fibres over time. For anything coloured, stick to white vinegar or an oxygen-based bleach. If you do use chlorine bleach on a plain white cushion, dilute it heavily and rinse twice as long as you think you need to.

Does sunlight really kill mould?

Ultraviolet light does slow mould growth and helps dry fabric, but it won’t kill established colonies on its own. Think of sunlight as a helper, not a solution. Clean first, then let the sun finish the job.

How often should I clean garden cushions?

Give them a proper clean at the start and end of the outdoor season, and spot-treat any damp patches immediately. If you live somewhere humid, add a mid-season check. Catching mould early saves hours of scrubbing later.

The Bottom Line

Mould on garden cushions is a nuisance, but it’s a solvable one. Assess the fabric first, treat it outdoors with a vinegar-based solution and a soft brush, rinse thoroughly, and dry the cushions standing on edge. Then fix your storage habits so the problem doesn’t come back next spring. Do that, and you’ll get years more use out of cushions you were ready to throw away.

If you want to go deeper on protecting outdoor furniture through every season — including covers, storage, and long-term care — there’s a more complete guide on the site that covers the whole picture.

Last updated 2026-09-24

Written by our editorial team at WiseHomeGuides, home and pet specialists.

Written by Rémy Bully

WiseHomeGuides publishes practical guides, comparisons and independent tests for home, bedding, garden and pets.

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