Asked on Jun 11, 2016

Removing lichen from granite?

My husband's grandmother's headstone is covered in lichen. It doesn't look very pretty, and it makes it difficult to read. The front of the granite stone is smooth and the sides and top of the headstone are rough-cut. I need advice on how to remove the lichen, and if possible, prevent it from growing back.
As you can see in the photos, there is a large honeysuckle shrub planted behind her marker. The shrub crowds the marker, but it cannot be removed, so I keep it trimmed back.
  18 answers
  • William William on Jun 11, 2016
    A gravestone should be cleaned and maintained carefully so as to avoid getting it scratched or tarnished. Thus, it is best to use a soft-bristle brush, or at most a plastic scraper or craft stick, instead of a wire brush or abrasive pad. Wet And Forget is the best one step tombstone cleaner. Wet & Forget easily removes moss, mold, mildew, algae, and lichen from historic monuments. Apply Wet & Forget to remove moss, remove lichen, remove algae, or mold and mildew from headstones. For best results apply heavy and leave it, just spray and walkway. Moreover, care should be taken so as to avoid cleaning with detergents that contain compounds like sodium bicarbonate, sodium chloride, sodium sulfate, ammonium carbonate, and trisodium phosphate (TSP or Calgon); they contribute in the build-up of soluble salts beneath the surface of the stone. Plus, avoid pressure washing a gravestone. Remember to wash the monument from the bottom to the top to minimize streaking and staining. As for the detergent, do not use a household cleaner like soap, borax, Spic and Span, Fantastik, Formula 409, muriatic acid, phosphoric acid, and other strong acids and bases as because they tend to be corrosive. Light colored marble or limestone tombstones can be cleaned with a cup of ammonium hydroxide or household ammonia mixed in a gallon of water to remove biological growth such as moss, mildew, algae, and lichen. Avoid using chlorine bleach, though, as they tend to result in light brown staining after some time. The best and safest means of cleaning a headstone is soft water. So, avoid using cleaning solutions as far as possible. If there appears lichen growth on the headstone in the form of grey and orange patches, then moisten the affected area and scrub it with a mixture of one part of ammonia and four parts of water. Finally, wash it with regular water.
    • See 3 previous
    • Annie Annie on Jun 16, 2021

      Gerry, check if you cannot get in there, check as they will ship many items to Canada.

      Sorry I don't think my first reply went through.

  • MN Mom MN Mom on Jun 11, 2016
    You should always consult the management of the cemetery to be sure you can make alterations of shrubs, etc as well as clean headstones yourself. They may very well have access to professionals who restor this type of monument. It might be worth your time to check and see if it can be done professionally.
  • Janet Pizaro Janet Pizaro on Jun 11, 2016
    I would not do anything until you speak to a groundskeeper per say at the cemetery.
  • Jim7311613 Jim7311613 on Jun 11, 2016
    the letters can be read, the aging of the stone with natures assist is the way it is, let it be and enjoy the imperfections they add character
    • Jennifer Thompson Jennifer Thompson on Jun 12, 2016
      The character is lovely but, sadly, the lichen is filling in the etched letters. It will only continue to grow & spread and it is our wish that we're able to read it for generations to come.
  • Beth Beth on Jun 11, 2016
    Go ahead and clean it if you dont nobody will
  • Elizabeth McCutcheon Elizabeth McCutcheon on Jun 11, 2016
    PLEASE LOOK UP HOW TO CLEAN A HEADSTONE. DO NOT USE PLASTIC OR ANYTHING COLOR. CLEANING CAN BE DONE WITH OUT HARMING THE STONE. OUR HISTORICAL COMMISSION HAS A GOOD SET OF RULES FOR CLEANING MANY TYPE OF STONES. IF YOU WOULD LIKE A SET SENT EMAIL WE CAN DO THAT. We have given several workshops with hands on and given out the instructions. I hope you do receive the instructions. It is not hard but takes time and lots of elbow grease.
  • Linda Hanson Linda Hanson on Jun 12, 2016
    I had the same problem with my parents head stones. Many stones in the cemetery are covered with a rusty orange coloured lichen and I emailed the headstone company that installed the head stone on my parents graves for advice. They recommended using a water and bleach solution and a stiff brush. I was worried about damaging the grass but they recommended doing it in the fall and just not over doing the cleaning process with to much bleach and water. I used a solution of 1/4 cup of bleach , a few drops of dish detergent and filled the rest with water. It was easiest to take the solution to the cemetery in 2 liter plastic drink bottles with screw caps . I also take several bottles of clear water to rinse off everything when I am done. Most cemeteries don't offer places to get water on site. It took some scrubbing and needs to be done every few years but does work. The stuff is so gross and STUBORN AS ANYTHING - it runs rampant in our cemetery. Even stones in full sun are covered.
    • Jennifer Thompson Jennifer Thompson on Jun 12, 2016
      Linda, thank you! These ingredients were my original thought but I lacked the knowledge so hearing that your monument company suggested it is a sigh of relief. One of the other Hometalkers recommended a product call Wet & Forget (readily available here in the US but also sold on Amazon) and it sounds like an even better product -- no laborious scrubbing, no toxins to harm the grass, it even works for about a year after helping to prevent repeat growth (!!!), and it's useful all around your home for outdoor furniture, patio cushions, siding, etc. It sounds too good to be true but I'll give it a try.
  • Jennifer Thompson Jennifer Thompson on Jun 12, 2016
    I love our Hometalk Community and the vast array of knowledge they're willing to share. William had the most in-depth suggestions and recommended a product (Wet & Forget) that, upon researching online, looks like it will be a godsend!
  • Peggy Havard Peggy Havard on Jun 12, 2016
    Thank you for taking the time for seeing about your husband grandmother grave, your heart is in the right place, xoxox. You might try 1/2 Vinegar, water and a drop or two of Dawn dish detergent & clorox, rinse with water as Linda state.... God Bless.
    • See 2 previous
    • Karen Karen on Jan 09, 2017

      We have similar stories, I totally believe that we have a special blessing as we do this. My parents did the same..... They needed some care but only minimal My inlaws needed a lot of help but didn't take care of their families the same way...... I wonder???????

  • B. Enne B. Enne on Jun 21, 2016
    Although it is probably not recommended, I used Scrubbing Bubbles aerosol foam, after rinsing the stone first (with a watering can) on a rainy day. I only left it for about 30 seconds then rinsed it off and the stone looked great. I was worried afterwards because I read that all kinds of things could happen if you use the wrong kind of cleaner (white or black deposits)., but it was fine, and it still looks good a year later. I wouldn't use it more than once a year if that. The stone is 20 +years old in a flat marker section, so it gets really dirty. It is the same colour as yours. I tried different granite cleaners, but they didn't help at all, and I didn't want to scratch the surface using brushes. The stone is partially polished and unpolished. I used the SB, because I had seen designers use it on sooty fireplaces on t.v., and it always seemed to do a good job. It did not kill the surrounding plants or grass.
  • John Abramo John Abramo on Jul 16, 2019

    I saw ammonia in a gallon of water to remove lichen. They said don't use bleach.

  • I would stay away from bleach since it can damage and yellow the stone. I would consider using a brush, water and a gentle soap. I know it will take some elbow grease, but it works. Preservation societies usually recommend water for organic matter removal.

  • Soak the headstone with a bucket of water and use a non-ionic cleaner with a soft brush.

  • Chloe Crabtree Chloe Crabtree on Jun 16, 2021

    Soak the stone with water and wait a few minutes. Gently remove loose materials from the surface. Once saturated, the lichens and moss on the stone will loosen and can be removed easily with a plastic scraper or wooden spatula. This helps remove the big particles so you will not be rubbing them back into the stone.

  • Maura White Maura White on Jun 17, 2021

    You can try this headstone cleaner:

    They have it at Walmart

  • Lori Lori on Jul 11, 2022

    D2 biological works great for headstone cleaning. You can order it from Amazon. I've used it and it removed all of the liken, algae, and discoloration off of the stone and will continue to do so as the cleaner continues to work. Follow the directions or watch a video on YouTube regarding D2 and headstone cleaning. You won't be disappointed!!

  • Mogie Mogie on Oct 15, 2022

    Where we laid my dad to rest part of the fee you pay is for upkeep they provide. Have you call them and asked what they use or recommend?