Lichen preservation on historic headstones

Historic headstones are more than markers of remembrance, they are valuable pieces of local history and heritage. Over time, many older memorials develop lichens, a natural growth formed by a symbiotic partnership between fungi and algae. The view on lichen on historic headstones is highly divided. Depending on who you ask - heritage conservators, environmentalists, or the families of the passed one - these colourful, crusty growths are viewed as either historical and ecological treasures or destructive and aestetic threats to the stone. This opinions makes lichen presence on historic headstones often more complex than it first appears. 

But why preserving lichen on historic headstones matter and how to find a middle ground? When caring for historic graves and memorials, it can be tempting to view lichen as something that should be removed. However, many conservation experts now recognise that lichens are often an important part of a headstone's history and character. Lichens are slow growing organisms that can remain on a stone surface for decades or even centuries. Their presence tells a story about the age of the memorial and the environment in which it has stood. In many historic churchyards and cemeteries, lichens also contribute to local biodiversity, providing habitat for tiny insects and other organisms. Lichen create miniature ecosystems on surfaces that would otherwise be bare stone. Contrary to popular belief, not all lichen growth is harmful. In some cases, lichens can form a protective layer that shields stone from direct exposure to sun, wind, and rain. Aggressive removal methods such as wire brushing, pressure washing, or harsh chemical treatments can cause more damage than the lichen itself, potentially eroding inscriptions and permanently harming fragile stone surfaces.

Is it possible then to find a middle ground to coexist of lichen and integrity of stone? The question is not simply whether lichen should be removed or left alone, but whether its presence is causing harm, obscuring important features, or contributing positively to the historic and ecological value of the monument. Many historic headstones have carried lichen for decades without suffering significant damage from it. By contrast, overly enthusiastic cleaning can remove the weathered surface of the stone, accelerate erosion, and permanently erase historic inscriptions.  A useful way to think about it is that a historic headstone serves two purposes: it is both a memorial and a small heritage habitat. Sensitive care seeks to respect both roles. Rather than aiming for a spotless appearance, the goal is to maintain the readability, stability, and dignity of the memorial while preserving the natural growth that have become part of its story.

For those interested in learning more about the role of lichens in historic churchyards and cemeteries, including their ecological importance, conservation considerations, and best practices for sensitive memorial care, a free mini guide is available to download below. The guide explores how it is often possible to achieve a balance between preserving valuable lichen communities and maintaining the legibility and long term integrity of historic headstones.