Operations director Michael Mann predicted the classic flowers would make a come back.
He explained: "Our sales were up on last year and we found an increasing amount of interest because there is a feeling of nostalgia about dahlias — people say granddad used to grow them. So we have tried to is show people you can use them in many different ways."
The move towards nostalgia in the garden was identified by Chris Beardshaw scholar and Bradstone Biodiversity garden designer Paul Hervey-Brookes.
Brookes said: "I think the nostalgia thing is spurred on by the recession and people escaping their immediate life and the garden can really do that. You see all these hideaways in the gardens here at the show and that is part of this retreat to the garden and recession thing, it really does make people feel nostalgic.
Mann said dahlia sales were also being influenced by the biodiversity trend, another key theme of the show.
He added: "Open pollinator forms are great for attracting bees and sales of the open pollinator types are up — if there is one major sales uplift it's in the single types, people are really looking for that."
RHS shows director Bob Sweet praised the Winchester growers stand for its riot of colour.
He said: "It is great to see the dahlias here, they really make an impact and they will go down very well with people. I think the stand looks fantastic and it defies all these predictions of a colourless show."
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