The Royal Horticultural Society (RHS) will map 400,000 garden plants growing across the UK, with the aim of developing the herbarium collection at the new RHS Hilltop Science Center.

Revealed as the largest plant-collecting exercise to date, the famous gardening charity has set itself an impressive goal of quadruple the number of plants inside RHS Hilltop in Wisley Garden – with a little bit of help from the public.

At present, the collection already has 90,000 plants, including a geranium from the place of death of Napoleon III’s son, the Prince Imperial, and a wild potato collected by Charles Darwin during the Voyage of the Beagle. With temperature, humidity and pest controls, the spacious atrium demonstrates the wellness benefits of gardens.

Britain’s largest herbarium dedicated to ornamental plants, Hilltop offers the best plant research and world-class collections, including the oldest specimen dating back to 1731. Now open to the public, it exists to help gardeners across the country tackle threats from pests and diseases, and mitigate the effects of climate change.

The extensive collection of plants is a permanent record of the UK’s horticultural heritage, providing a resource for future breeding programs. To help save British garden flora for the future, RHS Garden Wisley is currently recruiting plant enthusiasts, with the aim of opening applications in the remaining four RHS gardens next year.

Rhododendron ‘Louisa’ at the new RHS Hilltop gardening science center at RHS Garden Wisley in Surrey

Luke MacGregor / RHS

Volunteers will help the herbarium team select, collect, squeeze, mount and record UK Garden flora for the future, in RHS gardens, parks and gardens across the country.

Yvette Harvey, guardian of the RHS Herbarium, adds: “Herbaria are to plants what a register is to a classroom and a schedule is to trains. Records like these provide an important point of reference for what a given plant is and its uses – such as attraction to pollinators or the ability to capture carbon. Mapping these treasures is no easy task and we hope the public will be too eager to help us. ‘

Customers view the new Rhs Hilltop Gardening Science Center at the Rhs Garden Wisley in Surrey
Customers view the new RHS Hilltop Garden Science Center at RHS Garden Wisley in Surrey

Luke MacGregor / RHS

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