RHS Expert Groups

There are seven RHS Expert Groups, who are a valuable source of horticultural expertise, bringing together passionate individuals from amateur, professional, and commercial backgrounds.

The members aren’t just plant enthusiasts – they volunteer their time to help shape the future of gardening, from advancing sustainable growing practices to expanding networks locally and internationally.

RHS Expert Groups play a crucial role in making expert gardening knowledge accessible, whether it’s sharing the best gardening advice with RHS members, inspiring beginner gardeners, or championing urban gardening, these groups help cultivate a greener, more knowledgeable, and more inclusive gardening community.

Their dedication ensures that horticultural knowledge continues to thrive and inspire future generations.

Formed in 1936 as the Joint Rock Garden Plant Committee, the group consists of experts in these specialised plants and their diverse growing conditions. As well as its own meetings, the group attends Alpine Garden Society and Scottish Rock Garden Club events all over the UK, judging and assessing rock garden and alpine plants for RHS Plant Awards, including the RHS Award of Garden Merit (AGM).

The group evolved in 2013 from the Daffodil & Tulip Committee, which was formed in 1884. Its wider remit now covers plants with bulbs and other subterranean storage organs, including corms, tubers and rhizomes. Its members also contribute to the production of the Daffodil, Snowdrop & Tulip Yearbook and help to organise and judge relevant plants at regional horticultural shows and competitions. The group has strong links internationally, particularly in the Netherlands, and representatives of the RHS Lily Group also sit on this group. The RHS is the International Cultivar Registration Authority for daffodils and lilies.

Formed in 1858, this is the oldest expert group and membership includes representatives from the RHS Fruit Group. Its members assist with the judging of fruit, vegetable and herb classes at horticultural competitions and shows and participate in cultivar identification at various locations. They also visit allotment sites in the UK to share their knowledge and contribute expertise to RHS apps and campaigns.

The group, formed in 1859 as the Floral Committee and renamed in 2005, has a huge remit covering hardy herbaceous perennials including carnations and pinks, chrysanthemums, delphiniums and grasses. Its members regularly contribute to many RHS Plant Trials and rolling reviews of the RHS Award of Garden Merit (AGM). They give talks and demonstrations at a variety of shows and events across the country. The RHS is the International Cultivar Registration Authority for Dahlia, Delphinium and Dianthus.

The group was formed in 1889 and holds meetings around the country, working with local orchid societies and assessing more than 200 orchids for RHS Plant Awards every year. It has strong international links and its members represent the group and the RHS at events all over the world. The group assists in the planning and delivery of the annual RHS Orchid Show. The RHS is also the International Cultivar Registration Authority for orchid hybrids.

Formed in 1963 and renamed in 2005, the group comprises experts in growing tender plants from around the world, which, in temperate climates, are normally grown under protection or as houseplants. Its annual programme of events includes talks and demonstrations at a variety of flower shows, along with visiting nurseries and gardens where the members can share their expertise and learn about new technology.

Formed in 1859 as part of the Floral Committee and renamed in 2005, the group is the source of expertise for hardy trees and shrubs, including old hybrid roses, rose species and hardy climbing plants. It makes study visits to important collections and has links with the International Dendrology Society and other societies, and membership includes representatives from the RHS Rhododendron, Camellia and Magnolia Group. The RHS is the International Cultivar Registration Authority for Clematis, conifers and Rhododendron.

The RHS Expert Group Annual Awards, launched in 2019, recognise individuals making significant contributions to plant groups in fields such as science, conservation, propagation, literature, journalism, and art. Open to both amateurs and professionals worldwide, these awards highlight those whose work enhances plant knowledge and inspires others. Winners are selected through nominations and voting within each RHS Expert Group and receive a certificate along with an engraved glass vase.