The RHS and Plant Heritage (previously the National Council for the Conservation of Plants and Gardens, NCCPG) share a common aim to support the conservation of garden plants.
There are currently 655 National Plant Collections, which conserve a defined group of plants (usually a genus) in cultivation. One of the requirements of a National Collection holder is to make a collection of herbarium specimens from their living collections.
The RHS Herbarium works in conjunction with the National Collection holder by offering advice and knowledge for the preparation and archiving of the specimens. It can also act as the repository for the herbarium collection once made, providing ideal storage conditions and easy access to anyone wanting to consult the material.
A Plant Heritage research student is sometimes also available to assist the collection holder in this capacity.
The RHS Herbarium is also working in conjunction with Plant Heritage and RBG Kew's Millennium Seed Bank in a pilot project to conserve garden plants through seedbanking.
Selected National Collections are making collections of seed from their plants to be deposited in the Millennium Seed Bank. A voucher specimen of the plant is then deposited in the RHS Herbarium.
The following genera in the RHS Herbarium have specimens collected from National Plant Collections: