Green tops to the walls of Königstein Castle – nature and heritage conservation combined.
Normally, vegetation is removed from the stonework prior to refurbishing a castle or castle ruins. Once the work is completed, the growth of new vegetation is seen as undesirable. However, one current research project at Königstein Castle in the Taunus region is pursuing an alternative path: Mosses, grasses and herbs are being deliberately planted on the tops of the refurbished stone walls.
The idea of promoting the growth of selected plants on the tops of the walls after their refurbishment means that the work at Königstein Castle is something of a pilot project. The site is being monitored for three years to discover which plants grow well on which mortars. After that, the aim is to establish whether the plants offer effective protection against temperature fluctuations and moisture in the stonework. This project could become a prototype, because protecting the tops of stone walls is a critical aspect at all castle ruins.