The Royal Horticultural Society launched the revised Award of Garden Merit (AGM)
plant list at the Plant and Design show on February 19th 2013. The Award is intended to be a practical guide for all gardeners to help highlight plants and varieties which the Society knows to perform well.
The AGM is awarded only to plants that are:
• Excellent for ordinary use in appropriate conditions
• Of good constitution
• Essentially stable in form and colour
• Reasonably resistant to pests and diseases
• Available to buy in the UK
Potential AGM plants are nominated through two main routes – either by recommendations from RHS Plant Committees and specialists, or as a result of an RHS Plant Trial.
Originally compiled in 1992, the list has been completely reviewed by RHS Plant Committees, whose members include nurserymen and leading horticulturists, with assistance from plant societies and plant-group specialists.
For accuracy the RHS list should be considered the definitive list. The 2013 Ornamentals list can be found here