"It costs too much to get in - £50 for a couple. People are more interested now in spending that money on local nurseries," he said.
Harbutt has been dropped from all RHS shows this year and is selling at plant fairs and local agricultural shows instead. "If the gate price is reasonable I give it a bash and if the price is reasonable people have still got money in their pocket to buy plants."
An RHS representative said: "Judging on ticket sales in comparison to other events I'd disagree we're too expensive. Last year numbers at our shows were up quite significantly. Chelsea tickets are selling really well and we'd expect to be sold out before the show again."
Meanwhile, exhibitors have expressed reservations about the RHS Malvern Spring Festival (9-12 May) name change - previously Malvern Spring Gardening Show - and the cut in its grower exhibitors.
Potash Nurseries owner Mike Clare said: "People will be able to tell. I don't see the need to change the name because it was well established. Sometimes, if it's not broke, why fix it?"
Avon Bulbs owner Chris Ireland-Jones added: "I suppose it's inevitable but I don't really approve about going away from what ought to be a horticulturally-based show. It's broadening the base or taking away the emphasis."
Three Counties Showground communications manager Sharon Gilbert said: "We've always had food at the spring gardening show but we wanted to increase the connection between what we grow and what we eat to widen the audience.
"We have 80 exhibitors in the floral marquee when there are usually 100 because of the new shape and because we want to make sure there's plenty of space to move around. We need to do something to make the visitor experience better and to ring the changes."
Elsewhere, the RHS has waived exhibitor fees after the first of its new monthly London Secret Sunday shows on 6 April, which aimed to combine food producers, grow your own, folk music and performance artists. Just six nurseries exhibited at the first event.
"It didn't quite happen," said Hardy's Cottage Garden Plants owner Rob Hardy. "I think they're looking for a different market and struggling to find it. My argument is there was a big plant-buying market in London and that should have been provided for first, then add grow your own and the rest. They've tried to change it too quickly."
An RHS representative said: "We had 630 visitors, which was the number we were expecting. We were pleased with the numbers but we have looked at the model and have refunded some exhibitors. We will continue with the show and for a first show that was healthy."
Entry prices - How the main shows compare
RHS Chelsea Flower Show up to £68
RHS Malvern Spring Festival (on the gate) £38
RHS Flower Show Tatton Park (on the gate) £29.50
RHS Hampton Court Palace Flower Show up to £35
Shrewsbury Flower Show (on the gate) £26
BBC Gardeners' World Live (in advance) £22.50
Southport Flower Show (on the gate) £22
Harrogate Flower Show (on the gate) £17
- Provisional figures for Harrogate Spring Flower Show were 58,000 - six per cent up.
- RHS Flower Show Cardiff attracted 22,000 - the same as in 2013.
- The Edible Garden Show at Alexandra Palace attracted 12,064 - there were 13,000 visitors in 2012, when it was at Stoneleigh.