08/26/2026
THIS IS AN EDUCATION POST BUT ALSO A LITTLE RANT
I’m honestly starting to get tired of the amount of false information being spread about leaving moss and lichen on headstones—and then watching people get defensive when they are corrected with actual preservation information.
Let’s be very clear: moss and lichen are not harmless decorations on a headstone. Yes, they may look beautiful. Yes, they can give a cemetery that “old” appearance. But preservation is not about whether biological growth looks pretty. It is about protecting the historic material underneath it.
The National Park Service specifically identifies biological growth—including moss and lichen—as a threat that can cause deterioration and decay of grave markers.
And no, I’m not saying this because I personally “don’t like lichen.” The information comes from preservation science.
Lichen is a living organism. It retains moisture against the surface of the stone and can contribute to biological and physical deterioration. Lichens and other microorganisms can also produce and release acidic compounds that chemically interact with the stone. These biological processes can attack mineral surfaces, contribute to decay, and pe*****te weathered and porous stone. The National Park Service also notes that biological organisms and microbes associated with stone can produce acidic byproducts that weaken the material.
And yes, that includes Sunburst Lichen, the bright orange lichen commonly found on headstones. Calling it “natural” does not automatically mean it is harmless to historic stone. Sunburst Lichen is still biological growth attached directly to the surface, and it can be incredibly stubborn. If left in place, it can contribute to moisture retention and ongoing biological deterioration.
These photos are a perfect example of why people need to stop judging the results of preservation work immediately after the stone is cleaned. The order of these photos is:
Before cleaning → After cleaning → A couple weeks later → End of season → One year later
Notice something important: the damage did not magically disappear. While the biological growth was safely removed, the severe damage caused over time by the Sunburst Lichen remained. The lichen may be gone, but the deterioration it left behind cannot simply be washed away. That is exactly why leaving harmful biological growth on a headstone is not harmless—it can cause damage that is permanent.
The goal of preservation is not to make a stone look brand new. The goal is to stop or slow further deterioration and preserve what remains for as long as possible.
Here is what I need people to understand:
You are absolutely allowed to appreciate moss and lichen. But please stop telling others that it is completely harmless to headstones. That simply is not supported by professional preservation guidance.
Likewise, removing biological growth does not mean you can attack a stone with bleach, wire brushes, pressure washers, harsh acids, power tools, or whatever else someone saw in a viral video. Proper preservation means using the gentlest and least invasive method possible, evaluating the condition of the stone, and allowing time and patience to do their job.
We need to stop spreading myths and start listening to preservation professionals and the research that has been conducted on historic stone.
Because these headstones are not going to last forever—and misinformation is not helping preserve them.
