The RHS Award of Garden Merit (AGM) helps gardeners choose the best plants for their garden. You may well have seen the AGM logo. A cup symbol on a plant’s label shows that it has earned the AGM – it's the RHS seal of approval that the plant performs reliably in the garden. Awards are usually given after a trial period at an RHS Garden, often Wisley, and are judged by RHS expert forums.
RHS awards can also be given by 'round table assessment'. This is given when a forum of horticultural experts meet to debate the characteristics and garden performance of plants that the Society is unable to trial in one of the RHS gardens.