The Award of Garden Merit review 2012 Mike Grant

or over 150 years the RHS trial judges assessing Sedum for AGMs The Award of RHS has given awards to Garden Merit list of F exhibited at shows, The current review and continues to do so. The ranks When the AGM was relaunched in recommended plants of First Class Certificate, Award 1992 it was envisaged that there has just undergone of Merit and Preliminary Commend­ would be a so-called ‘sunset review’ ation are rightly valued, but they are every 10 years, when the list would its first review for awards given to that specimen on be scrutinized and less than excellent 10 years. John that day, as exhibited. Since 1922 plants excluded. Such a review took rimshaw the Award of Garden Merit (AGM) place in 2002 and has again G explains has been available to recognize plants happened in 2012. Much has the process and for their overall garden performance. changed, however, in 20 years. By the 1980s, however, it had fallen So, prior to starting work in 2012, reveals how it will be into disuse, and so was reinvigorated the remit for the AGM was studied done in the future in 1992 to become the Society’s by a working group led by Raymond premier accolade, granted to plants Evison (RHS Horticulture Board), that show consistent excellence in consisting of Jim Gardiner (Director the garden. ‘Plants that Perform’ is of Horticulture), Kylie Balmain the current marketing banner being (Head of Horticultural Relations), used to promote the AGM, and RHS trials staff, members of RHS sums up the concept very well. committees and represent­

20 March 2013 PlantsmanThe atives of the nursery industry. This Available in the trade group confirmed the desirability and at some level value of the AGM, established a The award plant should be available crisply redesigned ‘trophy’ logo in the UK from nurseries, seed (which has already been in use for suppliers, specialist growers or two years), and critically examined garden centres, either through retail the parameters for the award. outlets or online. Some plants, e.g. Five criteria for granting an AGM alpines, would be of more limited were established (see panel below) availability than bedding plants: and a series of guidelines was formul­ availability needs to be defined ated to assist in deliberations. appropriately for each plant group. The plant should also be at a reason­ Excellence for ordinary use able price for its type. in appropriate conditions Availability has been the most We made the assumption that the contentious of the criteria. In the plant is sold with information to 2002 review an AGM plant was make the buyer aware of appropriate expected to be sold by a minimum

growing conditions. For example, a of six nurseries (as listed in the RHS / RHS Henricot Beatrice Rhododendron may be AGM-worthy Plant Finder), but this approach was on acidic ground, but not on alkaline specifically rejected in the current RHS trials are one means of AGM assessment. This Buddleja succumbed to Phytophthora soil. ‘Garden’ was defined as any space review. Much has changed in the used for growing plants, enabling marketing of plants. The majority plants, such as Chamaecyparis houseplants to be included. But an of sales take place through garden lawsoniana ‘Intertexta’, no longer AGM plant must not require highly centres which seldom list their wares meet the availability criterion and specialist growing conditions or care. in the RHS Plant Finder, and there is have been removed from the list. Assessors of plants are expected to an increasing internet-based market. A particular challenge has come to set a particular standard against which It is also quite easy for a nursery to light in the case of annuals, bedding each plant is to be judged: if a plant miss the deadline for inclusion in the plants and many flowering house­ equals or exceeds the standard, it RHS Plant Finder and thus give a plants. In these categories there is a may be recommended for the AGM. false impression of non-availability. rapid turnover of and many There is no limit on the number of In some cases the merits of new or are not sold by name at all. For plants that may hold the award, but currently unfamiliar plants are so instance, the customer may just be in groups that include many cultivars, obvious that an AGM has been offered ‘orange busy lizzie’ or ‘blue standards have to be set especially granted. This may be before they are pansy’, despite the marketing effort high if the AGM is to offer helpful widely grown, in the hope that the put in by the breeders. A classic case guidance to the gardener. This award will stimulate propagation and that baffled the Tender Ornamental standard should be regularly distribution. Others, whose qualities Plants Committee was florists’ reviewed; the bar may need to be need further assessment, have been Cyclamen, where, despite the raised regularly, particularly in plant placed on ‘watch lists’ for consider­ presence in the market of a large groups where lots of breeding work ation in future years. Sadly, some number of named seed-raised is being undertaken. formerly well-respected AGM cultivars, none are sold under their cultivar names. Apparently the criteria for granting an Award of garden merit public only want a red- or pink- 1 Excellent for ordinary use in appropriate conditions – a cultivar or selection out- flowered plant, and that is what they performs others, e.g. more flowers, length of flowering, scent, colour, form etc. are offered. In consequence, it was 2 Available to buy – gardeners can obtain material without significant effort, at a decided that, since the public cannot reasonable price in reasonable quantity. buy such plants true to name, they 3 Of good constitution – the material is known to be generally healthy. should not be granted an AGM. The 4 Essentially stable in form and colour – performs according to its description. challenge of giving RHS recognition 5 Reasonably resistant to pests and diseases – no significant pest and disease issues which would affect growth and performance. to these ephemeral but significant groups is being considered. ➤

March 2013 21 PLANT awards

Of good constitution This refers to persistence in performance appropriate to the plant type. Stock should generally be healthy in the trade and cultivars which have declined over the years should be considered for deletion. Also, the plant must not require highly specialist care or treatment.

Essentially stable in form and colour Adherence to characteristics for

which the plant was selected, such as / RHS Sheppard Carol Sleigh / RHS Mike floriferousness, is essential. Cultivars should be stable in form and colour and known to be stable over an appropriate period of time, depend­ ent on genus. This is particularly relevant for variegated plants. Fundamental to the AGM criteria is the concept of consistency. A person buying an AGM plant must be assured that it really will perform to expectation. One of the weak points in the system is the granting of an AGM to a with no further distinction, effectively suggesting that the AGM pertains to / RHS Phillips Barry all representatives of that species. Various species have had their AGMs withdrawn because of inherent variability. They have been replaced This is undesirable, as the natural by more reliable cultivars of those same species, such as (clockwise, from top left)Cotinus coggygria variation inherent in wild species can ‘Young Lady’, Betula albosinensis ‘Red Panda’ and Rhus typhina Radiance (‘Sinrus’) result in wildly varying performance. In consequence, we are trying to give parents, vary greatly. As most The situation is also complicated the AGM to named cultivars rather specimens of it are raised from seed by the fact that many plants sold by than just ‘the species’, to guarantee the inherent uncertainty as to their nurseries under a species name are in consistent performance. qualities makes it impossible to fact clonal representatives of their This is not as easy as it sounds: award an AGM in this group. species (and probably should have a there are many species whose garden Perhaps the increasing availability of cultivar name). In such cases the plant performance as a whole is of AGM tissue-cultured clones with supplied to a customer is going to be standard, even when raised from consistent characteristics will permit consistent to its clonal attributes and seed – Acacia dealbata, Cyclamen it in the future, if they meet the it can be safely given the AGM, such hederifolium and commutatum other requirements. as Phyllostachys aurea. An example of ‘Ladybird’ for example, but in others Examples of where we have been a common clone that has been there is too much variation. The able to remove the AGM from the named and given the AGM is Sorbus situation with Helleborus x hybridus, species but apply it to cultivars thibetica ‘John Mitchell’. It is to be although not a natural species, is a include Betula albosinensis ‘China hoped that in the ongoing classic example. While few would Ruby’ and ‘Red Panda’, Cotinus assessment of plants the number of argue that the Lenten rose is a coggygria ‘Young Lady’ and Rhus species with the AGM will diminish superb garden plant, most are aware typhina Radiance (‘Sinrus’) and Tiger in favour of named clones that seedlings, even from good Eyes (‘Bailtiger’). representing them more reliably.

22 March 2013 PlantsmanThe Carol Sheppard / RHS Wendy Wesley / RHS

wild. Many of these were never going to be AGM plants and the undesir­ ability of some, such as Impatiens glandulifera and Hydrocotyle ranunculoides, is self-evident. On the other hand, there will be many who regret the absence of Rosa rugosa, Cotoneaster horizontalis and other Cotoneaster from the list, but all can be damaging to wild habitats. Carol Sheppard / RHS

Mark Bolton / RHS Another area of difficulty is where good plants have become muddled in the trade, with perhaps two or more clones being sold under the same name. Should the AGM be Herbaceous plants that have received AGMs in the latest review include (clockwise, from top left) Aconitum ‘Stainless Steel’, Paeonia ‘Coral Charm’, Eucomis comosa ‘Sparkling Burgundy’ and denied to the original, if it is the Phlomis tuberosa ‘Amazone’ best, because of this? In the case of Chaenomeles x superba ‘Knap Hill Reasonably resistant pathogens, is a major reason for their Scarlet’ the Woody Plant Committee to pests and diseases exclusion. In the deliberations of the felt that the situation in the trade The award plant must exceed or Woody Plant Committee we have was so muddled that the AGM meet the standard of natural excluded all Fraxinus in the face of should be withdrawn from plants resistance for that genus or species. the probable serious epidemic of with this name. However, in the For example, potatoes should have Chalara just over the horizon. case of Photinia x fraseri ‘Red Robin’, some resistance to blight and Additionally, a number of otherwise although there is evidence that some Monarda should have mildew good Pinus, such as P. nigra and mislabelling occurs, the original is resistance. Any pest or disease P. sylvestris, have had to be excluded still the predominant clone supplied treatments, where necessary, on account of their susceptibility and still worthy of the AGM. need to be available to amateur to Dothistroma needle blight. Also, in this review, tender orchids gardeners. However, at the time have been granted AGMs. They of award, acknowledgement of Other factors were excluded following the 2002 susceptibility to known diseases A further criterion for exclusion review because availability and should be stated. from the AGM list is plants deemed correct naming were insufficient. The susceptibility of plants to invasive in wild habitats by Defra, However, the situation has now disease, especially in the current and which it is illegal to plant in such improved, especially in availability, turbulent times for new plant a way that they could establish in the and 35 now have the AGM. ➤

March 2013 23 PLANT awards

The AGM assessment process the sunset review consisted principally Plants are granted the AGM by two of checking the availability of select­ routes: recommendation and trials. ions that hold the AGM. It was In both cases the names brought found that of around 1,000 AGM forward must be submitted to the vegetables, about 400 were no relevant committee for ratification longer available, so these have been by a majority vote (having been deleted from the list. Ongoing trials previously voted on by those who will ensure the list is kept up to date. made the selections). Most plants The other route to the AGM is with the AGM have achieved that through RHS trials. The most status by common consent, having frequent location for this has been RHS proved themselves to be worthy over RHS Garden Wisley, although RHS many years in many gardens, and this trials are conducted at other gardens Heuchera ‘Smokey Rose’ is no longer available core changes only slightly from around the country. These trials are review to review. They can be said to visited at regular intervals – occurred with Heuchera and its be the backbone around which our sometimes every few days at the relatives which were last trialled in gardens are planted. peak of the season – by a panel of 2001 – several cultivars that In the 2012 review the AGM list judges and each entry is assessed. At performed well, such as Heuchera has been scrutinized by each of the the end of the trial the results are ‘Smoky Rose’ which is no longer plant committees, or a subcommittee analysed and recommendations for readily available, have been edged thereof. Each worked within its awards or deletions are made. out by new introductions. Both remit to exclude plants deemed RHS trials are an expensive and groups are popular, and commonly unworthy of the AGM, those that labour-intensive activity involving purchased by the public, even if are no longer available, and to debate large numbers of RHS staff and some cultivars do not survive in the recommendations for new awards. volunteer judges, but the result is an garden for as long as one might Precisely how this has been done objective assessment of the qualities expect. However, no recent, has depended on the committee. In of that particular group of plants. objective assessment for the AGM most cases small groups of members Inevitably, the nature of trials means has been done on them. There is with particular expertise were asked that comparatively few can be much to be said, at least in genera to review a range of genera before carried out each year, so it is not such as these, for a more flexible bringing their recommendations possible to conduct frequent reviews approach to trialling. New intro­ back to the committee for discussion in this way for any particular genus, ductions could be compared against and ratification. In areas where the even though the turnover of cultivars a benchmark of tried and tested committee’s expertise was wanting, in many genera is remarkably rapid. AGM-worthy cultivars, enabling the outside input has been sought. For A notable example of a genus AGM list to be kept current and example, the Woody Plant where a new trial is urgently required informative. Committee is short of rosarians, so is Echinacea. A trial that concluded in Although a huge number of David Clark, who was asked to lead 2003 looked only at E. purpurea and people, from the nursery trade, the review of roses, worked closely a few other species, granting 4 specialist societies and National with the Royal National Rose AGMs, of which two have been Plant Collections, as well as the Society and other enthusiasts to rescinded in the current review. That RHS, have devoted a great deal of develop the new list, a model trial just missed the boom in interest time to the 2012 AGM review, not example of collaboration. They in Echinacea. A similar situation has all groups of plants have made it met for a series of meetings through through the mill. One notable 2012, delaying the final meeting Rose agm figures exceptions is Lilium, for which a to enable a final assessment of Rose names in RHS Database: 11,013 review will be undertaken in 2013. reblooming cultivars. The result Commercially available 2011–12: 1,765 Aquatic plants are another under- is a robust list of 321 roses with AGMs from 2002: 237 represented class with, for example, Deleted AGMs: 68 AGMs (see panel, right). a wonderful diversity­ of recent New AGMs 2012: 152 For vegetables, however, where Total AGMs for roses 2012: 321 Nymphaea cultivars not yet the AGM is granted only after trial, recognized by the AGM.

24 March 2013 PlantsmanThe

tiny fraction of the available diversity of garden plants and promotes them heavily. They perceive there is a danger that AGM plants will dominate the nursery trade and oust other cultivars from production. In some cases this might be a good thing, knocking dull plants out of the picture, and indeed (apologies to Plant Heritage!) there is little point Mike Grant in anyone, commercial or amateur, growing superseded, second-rate plants. The ideal is that the AGM RHS trials, such as this current one of herbaceousPhlox , will yield new AGMs on a rolling basis list should inform the choice of a Hardiness ratings decennial reviews such as we have solid core of reliable plants around It cannot be expected that all plants just done. The new procedure for which diversity can flourish. will grow in all places. One of the recommendations for additions or Fortunately, most gardeners like major determinants of appropriate rescindments is that they can be diversity and are always looking for growing conditions is a plant’s brought to committee for an annual different things to try. As a quick hardiness, and a hardiness rating AGM debate, and anyone can look at the RHS Plant Finder will produced by the RHS has long been submit suggestions. Additions will demonstrate, the choice of plants used in conjunction with the AGM come into force once ratified, but available is vastly more diverse than to provide a simple indication of there will be a lag period of a year for the AGM list. appropriate conditions for the plant. deletions, enabling retail catalogues Until 2012 a scale of ratings H1 to remain accurate for their lifespan Conclusion (tender) to H4 (hardy) was used, but and allow the using-up of stocks of The 2012 review of the AGM has this has been superseded by an printed labels. Awards arising from been a collaborative effort by a large expanded scale, H1–H7, that gives a trials are unaffected. Notification number of people. They have given broader and more robust assessment of new awards and deletions will be a huge amount of time to bring their of a plant’s hardiness. The new made on the RHS website. expertise together and help the RHS definitions can be seen by searching Committees will also have in one of its primary aims, the for ‘Hardiness’ at: www.rhs.org.uk responsibility for monitoring the promotion of good horticulture – The advantage of the new system existing AGMs for viability, and the Society is extremely grateful is that it relates to plant tolerances, undertaking such reviews as are to them all. not broad, geographic, climatic necessary to maintain the AGM list It is ironic that, despite all this sweeps like the commonly used in good shape. The advantage of this effort, at the time of writing it is USDA hardiness zones. As before, system is that it will mean that there not possible to say precisely how an indication of hardiness will be is no backlog of selections to be many AGMs will be on the new given alongside the AGM symbol, deleted, as in the case of vegetables list published in February 2013: at least in relevant RHS publications. this time, and that new introduct­ discussions and debates are going These new ratings have had to be ions that prove worthy can quickly on up to the last minute. It is likely, decided upon during the review receive recognition. Clearly, the however, to be in the region of process, in itself a considerable rigour of the criteria must be 7,100. This will give plenty of choice amount of work. adhered to, and popularity must not from which to make a splendid be allowed to obscure genuine garden of ‘plants that perform’. Changes to come worth, but this will make the AGM The most significant change to the more responsive to the changing AGM procedure is that it will now retail availability of plants. John Grimshaw is Coordinator of be a rolling process. There will be A concern about the AGM, raised the 2012 AGM Review and AGM continuous evaluation, rather than especially by plantspeople and Review Leader for the RHS Woody the monumental and exhausting specialist nurseries, is that it selects a Plant Committee

March 2013 25