The AGM is intended to be of practical value to the home gardener. It is awarded therefore only to a plant that meets the following criteria:
The list will be reviewed on an annual basis and the trialling of plant groups under-represented on the revised list and plant groups that have undergone extensive breeding programmes in recent years will be made a priority. The plants themselves are not graded within the award, so no distinction is made between good and very good for instance, as long as a plant meets or exceeds the standards set it gains the award.
- It must be of outstanding excellence for ordinary garden decoration or use
- It must be available
- It must be of good constitution
- It must not require highly specialist growing conditions or care
- It must not be particularly susceptible to any pest or disease
- It must not be subject to an unreasonable degree of reversion in its vegetative or floral characteristics
The award list was started 1991 and has recently been fully reviewed by the various RHS Plant Committees that are made up from nurserymen leading horticulturists as well as members of key plant societies and plant-group specialists.
During the process of review that took place last year nearly 2,000 plants lost their awards and a further 1,500 were given awards for the first time. Such a comprehensive review ensures that the list remains current and applicable based on changes in availability, pests and other considerations.
The RHS have also launched their new hardiness ratings, which have been used to re-assess all AGM plants by using data on the plant’s ability to tolerate a range of weather conditions. The hardiness rating is an integral part of the AGM, and should be included in any citation of the award.
Jim Gardiner RHS Director of Horticulture said: "The creation of the new hardiness ratings and the revised AGM list underline just why the RHS exists, to share the best in gardening. The knowledge and expertise of our trials forums and plant committees, and their dedication to share that knowledge with all gardeners, has resulted in systems that will help ensure we can all make the very best decisions about the plants we purchase. On seeing the RHS AGM logo gardeners should be confident that the plants they are purchasing have been objectively assessed to ensure they will perform as described."
Check out http://www.rhs.org.uk/Plants for more details