A day out for volunteers in Upper Teesdale to learn about bog habitats. The peat was 3m thick where we stood, 3000 yrs old so the equivalent growth of 1mm = 1yr. This accumulates because of the very slow rate at which plant material decomposes in areas that are waterlogged. Blanket bog is “ombrotrophic”, that is, the water and mineral supply comes entirely from atmospheric sources (rainwater, mist, cloud-cover). The water chemistry is nutrient-poor and acidic and the habitat is dominated by acid-loving plant communities, especially Sphagnum mosses, which the volunteers helped to plant today.