How to clean outdoor cushions, including mildew and covers that zip off

Step by step: how to clean outdoor cushions, including mildew and covers that zip off

Safety first. Bleach is only for fabrics whose care tag says it is safe, such as solution-dyed acrylics like Sunbrella. Never mix bleach with vinegar, ammonia or other cleaners, wear gloves, and work outdoors. If mildew covers a large area or you are sensitive to mold, wear an N95 mask.

1. 1

   Read the care tag first

   Look for a tag on the cover or zipper flap. It tells you the fabric (solution-dyed acrylic, polyester or olefin), whether bleach is safe, and whether the cover can go in the washer. If there is no tag, treat it as not bleach-safe.

2. 2

   Brush or vacuum off loose dirt

   Take the cushions off the furniture and brush off leaves, pollen and dried dirt with a soft brush, or vacuum with the upholstery tool. Wet dirt turns into mud stains, so get it off dry.

3. 3

   Mix a mild soap solution

   Stir 1/4 cup of mild dish soap into 1 gallon of lukewarm water, which is the ratio Sunbrella gives for routine cleaning. Pour some into a spray bottle for small spots.

4. 4

   Scrub the whole face, seam to seam

   Spray or sponge the solution over the entire panel, not only the stain, and scrub gently with a soft brush. Cleaning seam to seam avoids the ring marks that spot-cleaning leaves. Let the solution soak in for a few minutes.

5. 5

   Treat mildew on bleach-safe fabric

   For mildew spots on bleach-safe fabric, mix 1 cup of bleach and 1/4 cup of dish soap per gallon of water. Spray it on, let it sit about 15 minutes, then scrub lightly. On other fabrics, use a cleaner labeled for that fabric instead.

6. 6

   Rinse until the water runs clear

   Hose the cushion thoroughly, front, back and sides, until you see no more suds. Soap left in the fabric attracts dirt and can leave a stiff, blotchy finish.

7. 7

   Squeeze out water and dry on edge

   Press out excess water with your hands or blot with a towel; do not wring the foam. Stand each cushion on its narrow edge in a sunny, breezy spot so water drains down and out, and flip it every few hours. Let it dry completely before you sit on it or store it.

Can you put outdoor cushion covers in the washing machine?

Yes, if the cover zips off and the care tag allows it. Sunbrella’s upholstery cleaning guide says to close the zippers, wash on a cold, delicate cycle with a normal amount of mild detergent, and always air-dry. Never put the cover or the foam in the dryer.

• Put the cover back on while it is still slightly damp; it stretches back into shape more easily and does not shrink tight.
• Do not machine wash the foam insert. Hose it off if needed and let it dry fully, standing on edge, before it goes back in.
• For mildew on bleach-safe covers, Sunbrella says you can add 1 cup of bleach to the cold wash.

How to remove common cushion stains

Treat a stain by type: water-based stains rinse out with soap, while oily stains need to be absorbed first. Act fast, because sun bakes stains in.

Sunbrella’s stain chart recommends absorbing oily spills with cornstarch before washing, and POLYWOOD’s cushion tips use the same 1/4 cup of dish soap per gallon for routine cleaning.

How to keep mildew from coming back

Keep the cushions dry: mildew grows on the dirt and body oils trapped in damp fabric and foam. The EPA’s mold cleanup guidance is blunt that the key to controlling mold is controlling moisture.

• Stand cushions on edge or bring them in before a storm, and after heavy rain prop them up to drain.
• Store them indoors or in a ventilated deck box over winter, only once they are bone dry.
• Rinse off sunscreen and sweat every few weeks in summer; they feed mildew.
• Wash the frames too, using our guide to cleaning outdoor furniture, so dirty slats do not re-soil clean cushions.

If foam smells musty even after it dries, mildew is inside the core. Replacing the insert is usually easier than trying to clean it, and our musty smell guide covers the rest of the patio storage area.

Mistakes to avoid

• Using bleach on polyester or printed cushions whose tag does not say bleach-safe, which leaves pale blotches.
• Scrubbing only the stain, which leaves a ring once the fabric dries.
• Not rinsing until the suds are gone, so the fabric stays sticky and gets dirty faster.
• Pressure washing cushions, which drives water deep into the foam and can fray seams.
• Putting covers or foam in the dryer, which can shrink covers and damage foam.
• Storing cushions before the foam core is fully dry.