Unsightly and stubborn, black and white spots on slabs are some of the trickiest blemishes to remove from patios, and if you don't care for your stone paving properly, they'll more than likely regrow rapidly. These form when tiny lichen particles are carried in the wind and land on your patio or . From here, the lichen spores will then burrow into your paving and put down roots to establish a firm anchor from which to grow and spread.

Fortunately, even though white spots on patio slabs are fairly common, they're also easily treatable with the right know-how. Speaking exclusively to Express.co.uk, expert and CEO of , an outdoor construction company, Jenny He, has shared her go-to remedy after countless encounters dealing with these patio stains.

She said: "I've seen black spots on patios countless times in over 25,000 outdoor projects. These stubborn mold, mildew, algae, or grime marks can ruin a beautifully designed outdoor space.

"I've tried many methods to remove them, and some of the best are unconventional."

Sharing methods that are natural and don't involve the use of a pressure washer, Jenny ranked hydrogen peroxide as the best solution to opt for. She said: "This unconventional method can remove even the toughest stains without damaging the patio."

Hydrogen peroxide is a mild antiseptic, disinfectant, and bleaching agent. When applied to stains, it releases oxygen, which breaks down the chemical bonds in the stain's molecules. This reaction lifts the stain, making it easier to wipe away.

She continued: "I find diluted hydrogen peroxide very effective. Hydrogen peroxide is plant-safe and eco-friendly, unlike bleach."

Mix one part hydrogen peroxide with three parts water in a spray bottle, apply to black spots, and let sit for 10 to 15 minutes before scrubbing with a stiff brush.

Jenny pointed out: "One large stone patio owner was amazed when this method restored the surface without discolouration, something they'd struggled with when using bleach."

Another option is to try and , however, this will take longer to see results. Pour vinegar on the spots, sprinkle baking soda on top, and let it fizz and work into the grime for 20 minutes before scrubbing.

Jenny claimed: "One of my homeowners used this method on a brick patio to remove years of dirt without damaging it."