He said shows such as Countryfile, Top Gear, Masterchef and The Great British Bake Off have been allowed to grow, often starting on BBC2 and moving to BBC1 as audiences expanded. "It's about building and having faith. That's what happened with the big shows, people stuck with them." Bake Off attracted 15 million viewers for its final BBC appearance last month.
Buckland, whose Toby's Garden Festival takes place at Powderham Castle near Exeter in Devon on 28-29 April and has a new garden festival at Forde Abbey in Somerset on 16-17 September, added: "Fifteen or 20 years ago it would be considered unbelievable to have a cake-making show on television, even though there were lots of food shows. But they were often with men in whites. Gardening TV must come across like this sometimes, a bit elitist, when at its at its most successful it isn't, like Groundforce."
He explained that what is needed in gardening TV is "relevant advice" rather than a back-to-basics approach because "anything you didn't know is relevant. If you do know it's 'tell me something I didn't know'. That's the thing with Bake Off. Everything can be actioned. It's just a matter of getting the right size bake tin."
Buckland added that he hopes Brexit will give British nurseries more chance to shine and said at his shows he aims to bring in local growers who raise their own stock rather than buy it in.
Celebrity speakers Adam Frost and Pippa Greenwood will appear at Powderham, with more than 100 plant nurseries, arts and crafts, local food, live music and entertainment. Jim Buttress is also a guest and plant societies and garden clubs are particularly welcomed with group discounts and sale-or-return tickets.
Buckland said new BBC Gardeners' World presenter Frost "is widely tipped to be the nation's next head gardener". Charlie Dimmock and Christine Walkden are speakers at Forde.