How to Get Mildew Out of Outdoor Cushions

Few things are as unwelcome as pulling out your porch cushions in spring and finding them spotted with mildew. Those fuzzy green, black, or white patches are common on outdoor cushions left damp, but in most cases you can clean them off and save the cushion. The trick is using the right method for your fabric. Here is how to get mildew out of outdoor cushions safely.

Quick answer: Brush off the loose mildew, then clean with a fabric appropriate solution. A white vinegar and water spray is safe on most fabrics, while a diluted bleach and mild soap solution works on solution dyed acrylics like Sunbrella but should not be used on other fabrics. Rinse thoroughly and dry completely in the sun, which kills remaining spores. Always check the care tag, and never use undiluted bleach, a pressure washer, or an abrasive pad.

First, Check Your Fabric

This is the step that protects your cushions. The safe cleaner depends entirely on the fabric. Solution dyed acrylics, the most common quality outdoor fabric, can handle a diluted bleach solution. Many other outdoor fabrics, and anything with a printed pattern or a coating, can be damaged or discolored by bleach. So before you reach for anything, find the care tag and follow it. When in doubt, start with the gentler vinegar method below.

The Gentle Method: Vinegar

White vinegar is safe on most outdoor fabrics and is a good first try. Mix equal parts white vinegar and water in a spray bottle, spray it generously onto the mildew, and let it sit for 15 to 20 minutes so it can break down the growth. Then scrub gently with a soft bristle brush in small circles, lifting the mildew rather than grinding it in. Rinse thoroughly with a hose, since leftover residue attracts dirt and future mildew, and dry the cushions fully in the sun.

The Stronger Method: Diluted Bleach for Acrylic Fabrics

For solution dyed acrylics like Sunbrella, the manufacturer recommended solution for mold and mildew is one cup of bleach and one fourth cup of mild soap per gallon of water. Spray it on the affected area, let it soak for about 15 minutes, then clean with a sponge or very soft brush. Rinse thoroughly and air dry. You can find the official instructions on the Sunbrella care page. For fabrics that are not bleach safe, an oxygen based cleaner such as the kind sold for laundry is a gentler alternative for stubborn stains.

What to Avoid

• Undiluted bleach, which can damage fibers and finishes.
• Bleach on fabrics that are not solution dyed acrylic, unless the care tag allows it.
• Pressure washers, which can blast apart the weave and the cushion.
• Abrasive pads or hard brushes, which wear away the protective finish and can void warranties.

Dry Fully and Protect

Drying is as important as cleaning. Stand the cushions upright so air reaches all sides, dry them in direct sun since the ultraviolet light kills lingering spores, and flip them halfway through. Once dry, you can restore the fabric’s water repellency with an outdoor fabric protector spray, which also helps resist future mildew. For broader cushion and chair care, see our guide on how to protect and maintain outdoor rocking chairs.

Preventing Mildew

Mildew thrives on damp and shade, so the best prevention is keeping cushions dry. Stand them up after rain so all sides can air out, store them in a dry box or bring them indoors when not in use, and make sure water can drain rather than pool on the seat. A little airflow goes a long way. Choosing the right fabric in the first place helps too, as we explain in our guide to the best outdoor rocking chair cushions.

Frequently Asked Questions

Can I use bleach on all outdoor cushions?
No. Diluted bleach is safe on solution dyed acrylics like Sunbrella, but it can damage other fabrics. Check the care tag, and use vinegar or an oxygen cleaner on non bleach safe fabrics.

Does vinegar really remove mildew?
Yes, white vinegar breaks down mildew and is safe on most fabrics. Let it soak, scrub gently, rinse, and dry in the sun for best results.

How do I stop mildew from coming back?
Keep cushions dry. Stand them up after rain, store them when not in use, and treat the fabric with a protector spray to restore water repellency.

You can find outdoor fabric cleaners and protector sprays on Amazon.

Always test any cleaner on a hidden area first and follow your cushion’s care label.