Amid many signs of improved quality, show gardens and floral exhibitors accrued higher-class medals than ever before.
RHS head of shows development Bob Sweet said: "It has been a very cold spring, which created a lot of discussion among the judges, so their meeting has been a lot more controversial than usual."
"The standard of the show gardens has improved considerably. The number of silver gilts goes up consistently, and the number of bronze medals comes down. There has been quite a shift to better-quality medals."
Among the 22 show gardens at Malvern this year, two received gold medals, five silver gilts, 11 silver and four bronze.
Some designers said they had struggled to source plants because of the cold weather. Chris Beardshaw Mentoring Scholarship winner and bronze medallist Maria Luisa Medina said: "It was difficult to prepare - I had planned to use some Irises, but I couldn't get them to flower in time."
Designer James Alexander-Sinclair said: "The winter has made life very difficult for people - you saw it at Cardiff, but you can't expect Chelsea plants here, and a lot of the things like the Aquilegias just aren't ready. The winter makes it harder and the nurserymen involved have done amazingly well."
RHS shows director Stephen Bennett said he was amazed that marquee exhibitors had produced such high quality in the face of tough conditions.
"The marquee is greener than normal, but I think it is refreshing and welcome."
Most marquee exhibitors said it was their most challenging show in years, with launches cancelled and displays fraught with cold.
Matthewman's Sweetpeas owner David Matthewman said: "I'm certain it's less colourful in here because of the winter. Some stands seem a little bit thinner, so I'm sure the winter has had an impact. You can't force sweetpeas, you have to keep the frost out but let them come on at their own pace, otherwise you have problems."
Peter Smith Alstroemerias sales representative Caroline Wood said the challenge had been in predicting what would be ready. It had to use cut flowers from a commercial grower instead of the Princess Lilies it had planned to show.
Wood said: "Customers get confused as they ask for the ones on the stand that aren't available - and the variety we were hoping to introduce here was too slow, so we will introduce it at Hampton Court."
Pheasant Acre Plants owner Rob Evans said: "We normally have Gladioli starting to flower at this time of year but it was difficult because the light levels were so low. But there is a lot more plant material than I expected to see here and the quality is very good."
Hoyland Plant Centre owner Stephen Hickman said this year's plans had been jeopardised by the Icelandic volcano because plants arriving from Colombia, the Mediterranean and the Far East were delayed.
But Broadleigh Bulbs owner Lady Christine Skelmersdale said she had benefited from the cold because she was able to use plants that would normally have gone over. "I have been able to do a display of wetland stuff, which was still going strong. But we had terrible trouble getting the tulips ready," she said.
Lyn Downes Award for the Best Floral Marquee Exhibit: Ian Butterfield - pleiones
Most Creative Exhibit: Hoyland Plant Centre - Agapanthus and Tulbaghia
People's Choice Award: Grange Farm Nurseries
Best in Show and Gold: Graduate Gardeners/Mark Draper, The Youth of Old Age
People's Choice: Jonathan Bishop, Hansel & Gretel Fairy Tale Garden.