A herbarium stores and preserves plants, creating a scientific and historical record of what grows in a particular place, or at a particular time. The RHS Herbarium is the largest in the UK dedicated to ornamental plants and contains more than 92,000 specimens. A herbarium can tell us a lot of information about plants, growing practices and environmental changes. Why not create your own herbarium in your garden, school or community to document the plants that are growing there?