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How To Clean Flagstone Patio: Try These 3 Ways

The best way to clean flagstone patio is with flagstone cleaner. It won’t stain or erode your stone and mortar. Don’t be afraid to clean flagstone with white vinegar diluted in equal parts of water. Cleaning flagstone with bleach is safe when following the usage directions printed on the label.

Tired of looking at your dirty flagstone patio? Can’t think of a way to clean those stubborn stains? 

I know exactly how to clean a flagstone patio without hiring a cleaning service

Simply follow my easy step-by-step instructions below to clean the stains and mildew off your flagstones, giving you the best results ever. See for yourself!

Swimming pool surrounded with flagstone flooring
Image credit:

Unsightly flagstones can quickly ruin your curb appeal, no matter how hard you try in other areas. I’ve always tried my best to keep up the appearance of my home. This inspired me to write a complete guide on how to clean flagstone patio without damaging it

Without any further ado, let’s jump right into the first tutorial!

Clean Flagstone With Flagstone Cleaner


  1. Flagstone cleaner
  2. Bucket
  3. Scrubbing brush
  4. Garden hose


This is how to clean flagstones with flagstone cleaner:

  1. Mix The Flagstone Cleaner

    Before you jump into mixing the flagstone cleaner, you should protect yourself with rubber gloves and safety glasses.
    You can now safely mix the flagstone cleaner with water, following the instructions printed on the back of the packaging. The mixing ratio varies from brand to brand. 
    The StoneTech Stone & Tile Cleaner calls for 2 oz of cleaner per 1 gallon of warm water for light jobs and 4 oz per 1 gallon of water for heavy jobs.

  2. Apply Flagstone Cleaner

    Apply the diluted flagstone cleaner to the surface using a stiff scrubbing broom or brush. But don’t scrub the flagstone just yet! Simply spread the cleaner all over the stone and mortar. Put a little extra cleaner on the stained areas

  3. Let The Cleaner Sit

    Let the solution sit for 2-3 minutes, or as instructed on the packaging. Give the flagstone cleaner time to break down the stains and kill the mildew.

  4. Scrub Away

    You can now scrub the flagstone with your stiff scrubbing brush. Work in sections, so you don’t miss any areas or corners. 
    Don’t be afraid to apply more cleaner to particularly dirty areas. Continue scrubbing until you are satisfied with the results. 

  5. Rinse The Flagstone Patio

    Rinse the cleaning solution off the flagstones using a garden hose. Push the excess water off the patio with your broom or a squeegee mop to expose any remaining spots. Apply the cleaner to the leftover stains and scrub them away. Rinse them off afterward. 

Clean Flagstone With Vinegar


  1. White vinegar
  2. Bucket
  3. Scrubbing brush 
  4. Garden pump sprayer
  5. Water hose


This is how to clean flagstones with vinegar.

1. Treat The Problem Areas First

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Assess the state of your flagstone patio and determine which areas need heavier treatment. Spray undiluted white vinegar directly on the stained or molded patch and scrub it a little with a hard-bristle brush. 

Leave the vinegar to soak for 30 minutes. When the timer goes off, take your hard-bristle brush and scrub the area thoroughly. 
Wash off the treated area with plenty of water. If you are satisfied with the results, you can move on to the next step.

2. Spray Diluted Vinegar On The Whole Surface

Dilute white vinegar with an equal amount of warm water. I don’t recommend using any other type of vinegar for this project because it might stain your beautiful flagstone. 

Spray the vinegar solution all over the flagstone patio using a garden pump sprayer, like this one. You can also use a mop or a sponge to spread the diluted vinegar onto the surface. Just remember to use rubber gloves when doing so. 

3. Rinse With Water

Leave the vinegar solution to sit for at least 30 minutes before rinsing it off with your garden hose. 

You can do this treatment once a month. Your gorgeous shaded patio (regardless of its look) may need some extra love and attention since mildew and algae love to grow in shaded spots

Try Cleaning Your Flagstones With Bleach


  1. Outdoor bleach
  2. Garden pump sprayer 
  3. Deck brush
  4. Garden hose


This is how to clean flagstones with bleach.

  1. Dilute The Bleach
How to use 30 seconds Outdoor Cleaner
Image credit:

First and foremost, protect yourself with rubber gloves and safety glasses. Wear old clothes that you won’t care about if they get stained with bleach. 

You can use straight outdoor bleach, like this one made by Clorox, or any other Sodium Hypochlorite-based product, like the popular 30 SECONDS Outdoor Cleaner. This product may not be marketed as bleach, but water solutions of Sodium Hypochlorite are commonly known as bleach

Dilute your outdoor bleach with water in the ratio suggested on the back of the container. For instance, the 30 SECONDS Outdoor Cleaner needs to be mixed with equal parts of water to achieve the 50/50 dilution. See picture above for reference. 

2. Do A Patch Test First

patch test on flagstone

Bleach is a potent substance that can damage and discolor your flagstones if not used correctly. You can see bleach damage on the limestone in the picture above. That is why I recommend you do a small patch test somewhere in the corner of your patio just to be sure. 

4. Treat The Stained Flagstone

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You can now spray your diluted bleach on the flagstones. Focus on areas that are affected by stains, mold, and algae. The next step you take depends on the product you are using. 

Some outdoor bleach products, including Clorox, call for scrubbing, while others leave it as an optional step. 

5. Let the Bleach Sit Before Rinsing

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Check the label for how long you should let the bleach sit on the flagstone to get the maximum results. The duration time varies depending on the surface you are cleaning. 

The 30 SECONDS Outdoor Cleaner needs to sit for 15 minutes on stone patios and only five minutes on wooden decks. 

When the timer goes off, rinse the flagstones with plenty of water to remove the bleach completely. 

How To Clean Flagstone Patio: My Final Thoughts

A flagstone patio is an expensive investment that will pay off only if you take good care of it. Stains and mold can quickly take over your beautiful natural stone if you don’t establish a good cleaning routine for it.

I don’t like seeing my hard-earned money go to waste. I am pretty sure you don’t either.

This is why I have decided to write this complete guide on how to clean flagstone patio – to help you and others increase the value of your property

Did you like my cleaning tutorials? Let me know in the comments below and feel free to share my tutorials on your social media. Your friends might be looking for the same cleaning solutions as you are!

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About The Author

Nadya Jones

Nadya's the creative mind behind this blog, sharing her passion for landscaping, gardening and making spaces that nourish the soul. An entrepreneur and writer based in Raleigh, NC, Nadya turns imaginative ideas into inspiration, fueling home and garden dreams. Though Nadya crafts gorgeous posts and photos showcasing lush yards or blooming gardens, the real magic happens behind the scenes where Nadya's partner Brett provides endless support, implementing each vision with care and dedication. Brett's the one ensuring her creative concepts come to life. At heart, Nadya remains an imaginative soul, forever dreaming of whimsical details, vibrant hues and lush landscapes. Each manicured edge or blossoming bloom fuels inspiration, expanding her vision of what's possible in design and life. She shares her love for landscaping, gardening, and outdoor design in her blog, the one you are visiting right now. If you are interested in the same things, be sure to check it out! Also, follow Nadya on Facebook, Twitter, Instagram, Pinterest, Flickr, and LinkedIn!

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