How to Clean Patio Cushions That Are Full of Mildew

Maybe you live in a humid area, or maybe you aren’t as great at remembering to bring in patio cushions as you’d like to be. Either way, you walk out onto your patio to enjoy a beautiful sunny day only to find your cushions covered in mildew stains. Yikes!

To clean patio cushions that are full of mildew, either use white vinegar for mild-to-moderate cases or a pressure washer for severe cases. To use white vinegar, fill a spray bottle with undiluted white vinegar and spray the cushion. Let the vinegar sit for 60 minutes before scrubbing and rinsing.

Mold VS Mildew | Are they Different?

Mold and mildew are technically different, in the way that a cherry tomato and nightshade plants are different.

Mold includes all types of microscopic fungi that grow using hyphae, or slender threadlike fibers. Molds can thrive on any organic matter, from clothing to paper to ceilings, when there’s enough moisture. Black mold is probably the most infamous, although many types of fungi are beneficial in the soil.

Mildew refers to only a few species of mold, but it is often used to refer to mold that grows outward on the surface rather than upward. They’re powdery dots that start off as white and turn brown. These often live on shower walls, windows, or other high moisture areas.

Both mold and mildew not only cause unsightly blemishes on fabrics, but they can cause health problems like allergic reactions, breathing troubles, asthma, and chronic fatigue.

Why Did My Patio Cushions Form Mildew?

Mildew requires three conditions to grow: food (such as organic material), water, and oxygen. If you live in a humid climate, you leave your cushions outside all the time in the rain, and/or you use lovely natural materials like cotton, you’re going to get mildew.

Poolside cushions are another vulnerable spot, as the air is more humid around a pool and you have wet people and towels laying over them.

How to Remove Mildew from Patio Cushions

The best way to remove mildew depends on how much mildew has grown and how deep it’s penetrated the cushion.

Mild-to-moderate mildew or provide preventative care: Use White Vinegar

Don’t break out the bleach yet. It turns out this common household item (white vinegar) can kill up to 82% of mold species and prevents further mold outbreaks on both porous and non-porous surfaces. It’ll also help get rid of that mildew odor.

How to use white vinegar to remove mold step-by-step:

  1. If you can remove the covers from the cushions, put them into the washing machine with 1 cup of distilled white vinegar in the fabric softener dispenser.
  2. Pour full-strength white distilled vinegar into a spray bottle.
  3. Spray the vinegar onto the cushion from all sides.
  4. Let the vinegar sit for at least 60 minutes.
  5. With warm water, scrub the cushions on all sides.
  6. Rinse the cushions with a clean damp cloth.
  7. Air out the cushions until completely dry.
  8. Regularly spray your cushions with vinegar to prevent mold and mildew from returning.

Heavy amounts or deeply penetrated mildew: Use Pressure Washer

If you have a pressure washer (or can buy, rent, or borrow one), and the mildew has penetrated the foam cushion or through the fabric of the pillow, then you’ll need a heavier duty option. Pressure washers can clean more deeply than a spritzer and vinegar, but it’s really easy to damage the cushion from too much pressure, so follow all the precautions below.

How to use a pressure washer to remove mold step-by-step:

  1. Attach the pressure washer to an outdoor water source and set the PSI to the lowest possible setting so it won’t damage the cushions.
  2. Pour the cleaner into the soap reservoir and attach the soap tip. (If adjustable, again, lowest possible pressure setting.)
  3. Lie the cushions flat on a dry surface, like a deck or a driveway.
  4. Standing 2 feet away to protect the cushion, soak the cushions with water.
  5. Apply the cleaner, moving the cleaning wand in horizontal sweeping movements to create suds.
  6. Let the soap rest for 3 minutes to penetrate the cushion, but don’t let it dry.
  7. Use the brush to scrub at mold and mildew.
  8. Rinse the cushions with water to remove all soap residue.
  9. Gently wring out the cushions to remove the excess water and set in a sunny, dry spot to dry completely.

Should I Use Bleach To Clean Up Mold?

The EPA recommends against using bleach to clean up mold, with the caveat that professional cleanup crews may use their judgment on a case-by-case basis. Sterilizing the affected area with bleach isn’t that effective when there are mold spores in the air. If that’s all that’s done, then the spores will land and start growing again. Fixing the root problem (too much humidity) will keep mold from sprouting in the first place.

Bleach also causes another problem for outdoor cushions — most materials will fade in color and bleach can destroy foam.

Try the vinegar method first before reaching for bleach. Check the label to see if it’s bleach safe and dilute it! Use only ½ cup of bleach in 1 gallon of water.

And if the mold problem is so pervasive through cushions that you can’t clean it through other methods, then it may be better to replace the items.

How to Prevent Mildew on Outdoor Cushions?

The best way to prevent mildew on outdoor cushions is to bring your cushions inside when they’re not in use.

If you forget and it rains, then move the cushions into a dry place with lots of ventilation so that they can quickly dry. Laundry racks are great for this. Flip them over every half hour to allow the entire cushion to dry.

If you live in a humid place or can never seem to remember to bring them in, invest in quality acrylic or olefin cushions. Yes, they’re not natural materials, but they’re more sustainable in the long run when you don’t have to replace your cushions every season.

In the off-season, store outdoor cushions in a well-ventilated, low humidity place.

And clean the cushions regularly. When you clean regularly, you stop mildew from penetrating deeper into the cushion, and you can use more natural, less toxic methods. Regularly spray your cushions with white vinegar and give them a light scrub.

Cleaning Patio Cushions FAQs

Can I Wash Patio Furniture Cushions in the Washing Machine?

Before throwing your cushions into a washing machine, check the care tags to see if they’re machine washable. If they don’t say machine washable, then using a washing machine will damage the fabric or the stuffing. If it is machine washable, then check that they fit in the washing machine with enough room to agitate.

If the cushion has a removable cover, you can put the cover in the washing machine without risking the foam core.

Can I Wash Patio Furniture Cushions with a Pressure Washer?

You can wash patio furniture cushions with a pressure washer if you wash them carefully. Set the pressure to the lowest possible setting, and if the soap tip is adjustable, set that to the lowest possible setting as well. Stand 2 feet back and place the cushions on a flat, dry surface.

However, outside of mold and mildew removal, there’s little reason to risk using a pressure washer.

How Do I Know When My Outdoor Cushions are Beyond Repair?

You know when your outdoor cushions are beyond repair when:

  • The mold or mildew have penetrated deeply through the foam, or
  • You cleaned the cushions thoroughly, but the mold persists.

Do I have to scrub off mold or is killing the mildew enough?

If you have a mold allergy, then killing the mildew isn’t enough. Dead mold can cause allergic reactions in some people. That’s why you need to scrub the mildew off as well, even when the discoloration is hidden.

Final Thoughts

Mold or mildew on your patio cushions may be unsightly and worrying, but don’t panic. With a couple of thorough cleaning methods, like white vinegar or pressure washing, you can remove anything but extreme cases.

An ounce of prevention is worth a pound in cure! Bring in your cushions, thoroughly dry them if you forget, and regularly spray them down with white vinegar.



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