Matt Oliver talks to the baking star who is to open the Blenheim Palace Flower Show

It is only in its third year, but already the Blenheim Palace Flower Show has an enthusiastic endorsement from Mary Berry.

“From what I have heard it’s like Hampton Court, but in the countryside”, the Great British Bake Off judge says, who, it turns out, is a keen gardener herself.

“I have been to Chelsea this year as well and loved it, but, of course, at Blenheim you can buy plants like at Hampton.”

Britain’s favourite grandmother is set to open this year’s show at Blenheim, when it returns to the Woodstock stately home from June 19 to 21.

The three-day event has already attracted a string of big sponsors, with presenter, author and garden designer Joe Swift also set to appear on Saturday, as well as former royal gardener Jim Buttress, a favourite of the BBC’s The Big Allotment Challenge.

This year also pay tribute to former Prime Minister Sir Winston Churchill, as part of the 50th anniversary commemorations of the wartime leader’s death.

Sir Winston was born at the palace in November 1874 and proposed to his future wife, Clementine, in its Temple of Diana in August 1908.

And in his honour this year’s flower show has a flagship 25,000 sq ft ‘Victory Pavilion’, featuring over 40 stunning floral displays and a selection of plants from the UK’s top nurseries.

There will also be two show gardens by landscape designers, ‘Winston’s Way’ and ‘Churchill’s Crescent’.

But it is the attraction of being able to buy plants at the show that Mary Berry particularly enjoys.

The 80-year-old, who lives in Penn, Buckinghamshire, told The Oxford Times: “We have got three-and-a-half acres here in our garden, so I love gardening.

“I like growing herbs, because of all the cooking I do, and we have an edible herb garden, as well as vegetables and flowers.

“I also have a picking bed and at the moment I’m testing for my television series, so I’m always cooking.

“This time of year we are doing things like risotto, pate and other seasonal dishes.”

The Bake Off star and author of more than 80 cookery books has become one of the nation’s best-loved figures and her latest television outing, Mary Berry’s Absolute Favourites, is airing on BBC Two each Friday.

But the flower show will be an outing close to the heart of the grandmother-of-five, who grew up with rationing and is an ambassador for the Royal Horticultural Society (RHS).

She added: “I’m encouraging everyone to enjoy gardening and get out there and do a bit for themselves.

“I think it is important that you grow your own. A lot of people have raised beds these days, which I think are excellent, both my children have them.

“I gardened a little with them when they were younger, but I didn’t really take it up properly until they’d flown the nest. Now I do it a lot more and I love getting out to do it.”

She is also keen for more schools and young people to take up the trowel.

“The RHS is doing a great job at getting more schools to garden and the less academic children tend to particularly enjoy growing things and taking them home.

“I think that’s lovely, more schools should be doing it.”

Baking and gardening lovers alike will also get a chance to quiz Berry after her opening of the flower show at 10am on Friday June 19, in a question and answer session that will follow at 11am.

She will also be available to sign copies of her books, the latest accompanying her new BBC show.

The flower show itself will run every day from 10am to 5pm and there will be free parking.

Over 300 exhibitors have now confirmed their attendance, with the latest including show partner Aston Martin Works, Arctic Cabins, Cotswolds Garden Flowers and Derbyshire Bonsai, as well as Daffodil Fudge, Farrow and Ball and Kit & Kaboodal.

But shopping is, of course, what draws most people to the show and – in addition to a myriad of floral specimens – the event this year will feature an eclectic selection of cabins, summer houses, sheds and garden offices.

Among the many exhibitors will be Derbyshire-based cabin manufacturer and retailer Arctic Cabins, which enjoyed record sales in 2014.

The firm will be displaying one of its 10-metre cabins, which seats 15 people.

Marketing manager Louise Jones said: “We often hear that people have been looking at conservatories but as they get very cold in the winter and very hot in the summer, they actually prefer our cabins because they are for all year round.

“Thanks to the special adaptable benches they are also great for sleepovers, creating a teenage den, a unique guest room or a very impressive ‘man cave’.”

At the Chelsea Flower Show earlier this year, glasshouses proved particularly popular, with one structure selling for £12,500 to a honeymoon couple.

A vibrant choice of plants and countryside home wares will also be joined by a choice of festival foods and drink.

Depending on their palates, visitors can opt for afternoon tea, a champagne bar, terrace cafe, pleasure garden deli or food van snacks, throughout the day.

The palace’s 2,000-acres of landscaped parkland – which visitors may explore, along with the pleasure and formal gardens, at no extra charge – are undoubtedly one of the day’s greatest pleasures as well.

Matt Upson, director of Aztec Events, which organises the show, said: “The flower show is going from strength to strength and in just three short years has firmly made its mark on the horticultural calendar. We sold out of stand space in record time. The picture-perfect backdrop really rivals those offered by Chelsea or Hampton Court.”

For more information or to book tickets to the 2015 Blenheim Palace Flower Show, visit blenheimflowershow.co.uk.

Advanced tickets are priced from £11 adults and £5.50 for children at the gate. Concessions and family tickets are also available.