Several new varieties were launched at the show's Midsummer's Rose Festival, where growers reported double-digit increases on 2009's healthy figures.
David Austin Roses technical manager Michael Marriott reported that the company had seen a 15 per cent rise in wholesale and five per cent more retail plants sold.
He said: "It's been a fabulous year for roses, one of the best ever. We've sold something like 50,000 more this year. They are doing well in the garden because we had that wet autumn and cold winter.
"US company Jackson and Perkins going bust could be good for us. We had pulled out of being associated with them, so that should help us increase our market share. Japan has been good and England has been good, too. In the US we have a representative who has sold out of next year's stock already."
Bill LeGrice launched two new varieties, including R. 'Drama Queen' with the help of Dame Judi Dench and he agreed that last winter was a key factor. He said: "A lot of roses can do with a definite cold spell because some of them were just keeping their leaf all the way through the year, which meant you ended up with this unhappy mix of new and old growth. But the cold winter helped put them into dormancy and give them loads of new growth. Rose sales generally are probably up five to 10 per cent."
Peter Beales customer service manager Simon White added: "Sales have been very good. Possibly the harsh winter is helping as people lost plants in the garden and want to replant. The bloom is good this year with lush growth and I'm putting it down to the winter."
Growers agreed that disease concerns are disappearing as recent breeding has helped resistance. Marriott said further breakthroughs are on the horizon. "Black Spot is the real problem but we are making progress. Our 2013 introductions are a super-looking group of varieties and they've made an excellent step forward."