RHS judging panels for flower shows should include non-horticulturists to open up a process seen as arcane and secretive, leading designer Tom Stuart-Smith has said.
Speaking at an RHS conference on Monday examining plans to change judging techniques, the multiple Chelsea gold award winner said: "An external perspective is important because people think that decisions are made that are not accountable in the wider sphere.
"I feel strongly that the RHS should consider one or two people with outside views - for example, architect Richard Rogers or a furniture designer. It needs to be someone who has the guts to say 'this may be great horticulture but it's a crap design'."
The debate at Lawrence Hall, Pimlico, was part of a review of the judging system for RHS show gardens. This was launched last November and followed mounting criticism that the process was complicated, confusing and opaque (HW, 9 December 2011).
RHS president Elizabeth Banks said: "This review of judging is about the RHS being a bit more open and a bit more transparent. We want everyone to have a better understanding of the process and that's why we are looking at changes."
A review panel, including Hillier Nurseries chairman Robert Hillier and celebrity designer James Alexander-Sinclair, is looking at every aspect of judging - from garden selection for shows to the award of medals - and is due to report in late March.
Mark Fane, who has won 12 Gold Medals at Chelsea, suggested a "wildcard" element for judging panels similar to the Booker Prize, which drew actors and famous PRs into panels. A noted architect or clothes designer would add "real gravitas", he said.
But Bob Sweet, who sits on the review panel, said the RHS needed total confidence in the skills of the judging panel. There had to be an agreed methodology and level of expertise to ensure that everyone was "singing off the same song sheet".
Sweet also urged caution on a "groundswell of opinion" that judges from nations such as the USA and Japan should be invited to join panels in response to a suggestion from garden designer Robert Myers.
"It would be a healthy addition to the current mix of judges and they wouldn't necessarily have to have a vote," said Myers. "Someone like Philippe Starck would bring in a fresh perspective."
But designer Julian Dowle said: "I have judged with people with incredible bias and ignorance. The standard of judging in this country is way above that of elsewhere."
RHS director-general Sue Biggs said: "RHS medals are the highest accolades in horticulture - even more reason never to be complacent and to ensure that standards are the best and most valued in the world. This review is not revolution, it's evolution."
The review panel will make a final decision on changes by the end of March.
Senior RHS judge Andrew Wilson defended the way that medals are awarded in response to criticism that the current system of scoring points is arbitrary.
"Criteria for assessment and judging are published," he said. "We work through the criteria and debate - it's not simply a case of saying 'let's give this one a seven'.
"The job of assessors is to ensure that there is full discussion. There is no railroading. It's about open views and that runs through the process so when we arrive at a final percentage we can say it equates to a Silver Gilt or a Gold."
Wilson disagreed with suggestions that the current system lacked transparency for using an empirical scoring system for something as emotional as judging garden design.
"That's too simplistic," he said. "There's a mix, not a division. One feeds into the other. It is not a separate or different process."
RHS flower shows - Garden judging review panel
Robert Hillier, panel chair, vice-president, RHS
Elizabeth Banks, president, RHS
Sue Biggs, director-general, RHS
Stephen Bennett, director of shows, RHS
Sir Anthony May, judge, non-council member
James Alexander-Sinclair, council member, RHS
Roger Platts, nurseryman, non-council member
Bob Sweet, head of shows development, RHS
Katie Shelmerdine, internal auditor, RHS