How Do You Get Mildew Stains Out of Patio Furniture and Outdoor Cushions?

Most mildew stains on patio furniture and outdoor cushions come off with a bleach-free cleaner, a soft brush, and a garden hose. Brush away loose dirt first, test the cleaner on a hidden spot of the fabric, apply it to the stained areas, give it a few minutes, scrub gently, and rinse well. Then let everything dry completely — in the sun if you can — before the cushions go back on the furniture or into storage.

You don't need a pressure washer, and on cushion fabric you shouldn't use one. It drives water deep into the foam, and that trapped moisture is how cushions end up musty in the first place.

One honest caveat before the steps: if the staining is widespread, keeps returning within days, or comes with a musty smell that never leaves, you have a moisture problem, not a cleaning problem. Cleaning removes the stains on the surface. Moisture is a separate fix.

Why furniture comes out of summer — or storage — looking like this

A humid season is hard on anything that lives outside. Vinyl straps, resin wicker, plastic arms, and cushion fabric all pick up that gray-green speckling, usually in the seams, the weave, and anywhere shade and still air meet.

Storage does it too. Cushions that go into a deck box or garage even slightly damp in the fall tend to come out spotted in the spring. That's not neglect. It's just what moisture does in a closed, dark space over a few months.

Step-by-step: cleaning mildew stains off patio furniture and cushions

You'll want a bleach-free cleaner made for mildew stains, a soft-bristle brush, a garden hose, and a dry day.

1. Pick a dry, sunny day. Drying matters as much as cleaning. Give yourself a full afternoon of sun.
2. Dry-brush everything first. Knock off loose dirt, pollen, and cobwebs with a dry brush. Run a vacuum along cushion seams if you have one handy.
3. Test a hidden spot on any fabric. The underside corner of a cushion is perfect. Apply the cleaner, wait a few minutes, rinse, and check the color once it's dry to the touch. Outdoor fabrics vary, and a few summers of sun can change how a dye behaves — a two-minute test saves a visible mistake.
4. Apply the cleaner to the stained areas. Work in sections so nothing dries out before you get to it.
5. Let it sit for a few minutes. Give it time to work on the stain before you start scrubbing.
6. Scrub gently. On fabric, go with the direction of the weave and let the cleaner do most of the work. On vinyl and resin, you can scrub with more confidence — a stiffer brush helps pull staining out of textured low spots.
7. Rinse thoroughly with the hose. Rinse until the water runs clean. If you're cleaning a patio table or anything else food touches, give those surfaces an extra rinse.
8. Dry completely. Stand cushions on edge so water drains from one corner, and flip them once during the afternoon. Never put a cushion away even slightly damp.
9. Repeat on stubborn spots. Stains that have been there a season or two often take a second pass. That's normal.

If pets share the patio with you, keep them off the furniture until everything is rinsed and fully dry.

The cleaner we make for this

We make Mold & Mildew Warrior for exactly this job. It's a plant-based liquid cleaner for mildew-stained and musty surfaces. The active ingredient is citric acid at 8.5%; the rest is water, ascorbic acid (vitamin C), and citrus pulp. No bleach, no harsh chemicals.

It comes in a 128 fl oz gallon jug, made in the USA, for $42.75 with free US shipping.

Frames vs. cushions: two different jobs

Vinyl, resin, and plastic frames are the easy part. The surface doesn't absorb much, so cleaner, brush, and rinse usually gets it done in one pass. Textured resin wicker holds staining down in the weave, so take your time there.

Cushions are the part that decides how the whole project goes. The fabric cleans up fine with the method above, but the real risk is what you can't see: water in the foam. If a cushion smells musty from deep inside even after the cover is clean and dry, moisture got into the foam — usually from damp storage. A few full days in the sun sometimes airs it out. If the smell keeps coming back, the foam itself may be past what surface cleaning can do.

While you're out there with the hose, take a look at the wall behind the furniture. If the same humid season got to your house too, here's our guide to getting mildew stains off vinyl siding without a pressure washer.

When it's more than a stain

Cleaning handles surface staining and musty odor. It does not fix the conditions that caused them. If stains return within days, if they cover a large and growing area, or if you're seeing mold inside a screened porch ceiling, walls, or anything connected to your home's HVAC, stop scrubbing and deal with the moisture — drainage, airflow, a leak, or a professional assessment. No cleaner is the answer to that situation, including ours.

FAQ

Can I just use bleach? Plenty of advice online says to. But bleach can pull color from outdoor fabric, and the runoff is rough on the grass and plants under your patio. It also does nothing about the moisture that caused the staining. We built our cleaner without it.

Is a cleaner like this safe around pets? "Safe" is a word we're careful with, and it's not a claim we make. Here's what we can tell you plainly: our cleaner is plant-based, has no bleach, uses citric acid as its active ingredient. Good practice with any cleaner: keep pets off surfaces until they're rinsed and fully dry, and rinse anything food touches. For anything involving your pet's health, talk to your vet.

Do I need a pressure washer? No — and on cushions it works against you by forcing water into the foam. A garden hose and a soft brush are all this job needs.

Will the stains come back? Stains are the symptom; moisture is the cause. Anything that stays damp in warm shade will eventually spot again. Dry cushions fully before storing them, store them somewhere with airflow, and tip furniture so water drains after rain. If stains return within days of cleaning, reread the section above — that's a moisture problem.

Can I machine wash cushion covers? Some covers zip off and have a care tag that allows it — follow the tag. Just remember the cover is only half the cushion. If the foam went into storage damp, a clean cover won't fix the smell.

---

If your patio set needs this once or twice a year, the Mold & Mildew Warrior gallon jug is the product we make for it — $42.75, 128 fl oz, free US shipping. We're a woman-owned family business in Santa Rosa Beach, Florida, making plant-based cleaners since 2015, and we know what a Gulf Coast summer does to outdoor furniture. You can read what other customers have said on our testimonials page.