Experts share the surprising reason you should be drying your laundry outside this summer, and it's got nothing to do with your energy bills

Laundry Drying
(Image credit: Shutterstock)

There's something charming about the image of clothes drying in the sun, but when you've got access to a clothes dryer, it can seem all too easy to toss your wet clothes straight to your go-to cycle. But according to laundry experts, there are reasons beyond energy-saving for drying your clothes the old-fashioned way.

Drying your laundry outside uses no electricity or chemicals, making it a more environmentally friendly option. It is also free, once you have a clothesline and some pegs to keep the clothes in place; you won’t be running up your electric bill, and there are no repairs or upgrades to make, unlike with a dryer. You might even get a more freshly scented load of laundry, thanks to the exposure to fresh air and lack of chemical products.

But my favorite and most surprising reason for drying my laundry outside? It has the upper hand on a dryer when it comes to white and light clothes, thanks to the sun’s secret power: stain removal.

Nature's stain remover

Lemons with piles of white laundry — (Image credit: Shutterstock)

“Sunshine is a natural brightener,” said the laundry care experts at ASKO. “After washing, hang whites outdoors when you can, as the sun’s UV rays help lift the remaining stains and restore that fresh, clean look without harsh chemicals or bleach.”

This isn’t an old wives’ tale; there is science to back this up. When you hang your laundry out to dry, you’re counting on the sun’s rays warming the fabric and evaporating the water away. This heat is what turns your wet garments into crisp, dry laundry.

“Sunshine is a natural brightener”

But the rays aren’t just warm, they’re also a form of light. Speaking scientifically, sunlight is just a simpler name for solar radiation, which in turn is a kind of electromagnetic radiation. Sunlight encompasses a range of the electromagnetic spectrum, including visible light, infrared (IR) light, and — crucially for your laundry — ultraviolet (UV) light.

UV rays are the part of sunlight that tans human skin, but they are also a natural bleaching agent. The UV light breaks down the chemical bond that forms between the stain and the clothes fabric, loosening its hold and making it easier to remove. Simply exposing the washed laundry to sunlight for a prolonged period can be more effective than pouring large quantities of bleach into the washing machine – and safer, since there are no synthetic chemical agents involved.

What stains are most effectively treated by sunlight?

A white shirt with a yellow stain — (Image credit: Shutterstock)

Since the sun removes stains through bleaching, it is most effective on white clothes or other light-colored fabrics. Stains on darker fabrics will be harder for the sun to penetrate and those clothes might become discolored by extended time in the sun. It is also very useful for removing yellowing from clothes, whether this is caused by food stains (turmeric, tomatoes, curry), or from perspiration.

Thinner fabrics will also respond better to this stain treatment than thicker ones. Only the upper surface of the fabric will be penetrated by the sunlight, so a stain that has soaked through several layers of material will be unlikely to budge without additional chemical treatment. Therefore, save this method for thin cotton clothing, rather than terrycloth robes or thick socks.

Expert tricks

Pink, blue and white bedding being on a clothesline outside on a bright sunny day — (Image credit: Getty Images)

To maximize the sun’s bleaching of your laundry, there are a few recommended actions to take:

Apply lemon juice to the stain before hanging the clothing in the sun. For really stubborn stains, apply lemon juice and salt to the area and then aggravate to make sure the lemon penetrates the fibers. Rinse, then apply more lemon juice and hang outside.
Lay the garment flat outside if the stain is large or in a strange area. This will ensure that the sun shines on the stain consistently.
Bring clothes indoors within 3 hours to prevent overbleaching. This can lead to permanent discoloration of your clothes.

More from Tom's Guide

Despite making her home in urban metropolises, Madeleine Streets has been nurturing a green thumb for decades.

Raised by a garden designer, she is putting that childhood education to use by helping others learn how to make their garden bloom, while filling her own New York home with cat-friendly plants.

When not writing about gardening and the outdoors, Madeleine loves to cook, study wine and borrow books from her local library.

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