Welcome to Tregothnan, England's only tea estate The success of the tea production has certainly changed the life of Boscawen, 57, a retiring, twice-married aristocrat who rarely gives interviews. "Until recently I wouldn't appear far from home if I didn't have to," he says, "but producing tea has enhanced my life. I now travel around the world looking at tea plantations. Last month Jonathan and I were invited to Number 10 Downing Street as part of the Government's Great Britain campaign to celebrate our success and discuss export opportunities. I've also been to a tea ceremony in Singapore, and Chinese state television came here to do a documentary on English tea. Boscawen's family has lived at Tregothnan, on the banks of the River Fal, since 1335; they made their money from farming and mining tin. The estate includes a 100-acre garden, 100-acre tea plantation and thousands of acres of farm and woodland. It is stunningly beautiful. And for generations the family has loved cultivating unusual plants - they were the first to bring camellias to Britain 200 years ago. There are now 2,000 varieties and one or other is guaranteed to flower every day of the year in every shade of red and pink. Some plants reach as high as 35ft. On my visit they clashed wonderfully with multicoloured rhododendrons, some of which are even taller. Equally stunning are the carpets of bluebells and wild primroses. But it was a Magnolia campbellii, with huge colourful flowers, and originally from north India, that became the source of inspiration and change. In 1999 Jones noticed it was flowering earlier in Cornwall than in Darjeeling. I thought if this tree can do as well as it does in India and we have no trouble growing camellias, why don't we try growing tea, which comes from a special form of Camellia sinensis? We have a marvellous maritime climate here, the soil is acid, there is plenty of moisture and it's very similar to the cool and rainy uplands in India where Darjeeling is grown. It was an opportunity to push the boundaries. That same year Jones organised for cuttings and seeds to be sent over from a contact in Darjeeling. "We did a small trial block in the kitchen garden so that if it was a failure we could quickly move on," he says. But the bushes did well and we felt we were on to something. We were ridiculed by people who said if it could be done it would have been done before. They also went on about disease. I decided not to take any notice. I then took a year out, which luckily was partly funded by a Nuffield Farming Scholarship, and travelled around the tea regions of the world to learn as much as I could. Jones came home loaded with cuttings. "Sometimes I had to dispense with my clothes to make room for my samples," he laughs. It takes five years before a tea bush can be harvested and at the beginning of 2005 we began to feel that perhaps we were complete idiots to take it on. But we sold our first tea in November of that year and since then it has been growing at an incredible rate. We now have plantations dotted all around the estate, each plantation no bigger than an acre to reduce the risk of spreading disease. We are propagating 6,000 tea bushes each year. Fortunately they thrive on rain and our three-year-old bushes are a year older in terms of size, whereas the tea-growing in Kenya has suffered this year because of a prolonged dry spell. White, green and black tea are all produced by the same bush, which grows from about 1ft to knee-high. The exclusive white tea comes from the thinnest wispy tip of the bush, green from the first two leaves and the roundish tip, and black tea from two leaves and a tip but with the odd extra leaf thrown in. Tea is picked every day from April to October by staff and volunteers. The pickings are left to wither a little, rolled to break down the cell walls for maximum flavour, then left to dry. The estate produces the bergamot-flavoured Earl Grey tea, named after Boscawen's ancestor Charles Grey, who was prime minister in the early 19th century. There are also lots of herbal teas, including the exotic manuka tea, from the manuka bush, source of the famous honey. "We are the only place outside New Zealand that has manuka bushes," Jones adds. We used to sell the foliage to florists to use in bouquets but since the honey has become so popular we are now producing honey itself. It's pure and exclusive and costs £50 a small pot. The estate's regular tea isn't cheap either: about 20 times a cup more than the regular mass-market blends. But they are not short of customers supplying such up-market concernds as the Savoy, Claridge's, and Fortnum & Mason. "Tea, like whisky, has various levels of quality," Boscawen explains as we sit under a vast red-flowering camellia. Before I got involved in tea production I didn't appreciate the difference between the various types. At one end there are the big blends like Typhoo and Brooke Bond, which are the equivalent of cheap own-brand whisky from supermarkets. At the other are the first plucking of tea from a single estate, which is absolutely pure, individual and so valuable it sells for £1,500 a kilo and can perhaps be thought of like a single malt. Jones learnt a great deal on his worldwide trip, including about the Wardian Case, a mini-greenhouse invented by Nathaniel Bagshaw Ward in the 1830s and used to transport tea bushes and rare plants such as manuka and Camellia sinensis around the world when there was limited water available on ships. It changed the horticultural world. To his enormous surprise, some time shortly after his return he found a Wardian Case in a locked shed on the estate. "It is the only one in existence," Boscawen confirms, "and was invented to take tea bushes from China to India at the time of the Opium Wars. It was addressed to Viscountess Falmouth, England, who was my great-great-great-grandmother, and been hidden away since 1850. It's marvellous to put plants in when you go on holiday. We are making replicas to take to Chelsea Flower Show next week. We shall be having two stands this year, one in the Great Pavilion with the Wardian Cases and another in the trade stand, celebrating magnolias and selling our tea. One of the many good things about tea is that even indulging in a luxurious brand won't bankrupt you. Many people doubted whether tea could be grown commercially in Britain, but we have proved it can, and this year we'll be harvesting about 10 tons. It is a drop in the Chinese tea ocean but extraordinary for a small enterprise. We feel the industry is on the cusp of a massive change and we're planning to open a tea shop in Shanghai by November and then a franchise of tea-houses in Britain named Festival of Tea, to give the coffee houses a run for their money. He smiles. The world's favourite beverage has finally found a home on British soil. Telegraph readers can order a Chelsea Flower Show reproduction Wardian Case with three Tregothnan tea bushes for £495, saving £200. Delivery June 2013. Contact tea@tregothnan.co.uk Chelsea Flower Show runs May 21-25