It's shortly after noon and the Tregothnan country estate is bathed in a low blanket of mist. Leaden skies loom overhead and a steady drizzle of rain makes the surrounding foliage glisten bright green.
For holidaymakers heading to this part of Cornwall it's not exactly enticing weather. But Jonathan Jones, the estate's garden director, couldn't be happier. "It's just perfect," he says. "The plants love it."
The plant Mr Jones is specifically talking about is one that is forever associated with England but, until recently, has never been grown here. Tea has always had to be imported, but in the space of just a few years Tregothnan has turned all that on its head. Thanks to Cornwall's warm and wet micro-climate, the estate is home to Britain's only commercial tea plantation.
The adventure began as a somewhat hare-brained idea with the first harvest producing just 28 grams. Now the estate churns out 10 tons of tea and even exports its produce to India and China.
Cornwall works as a tea-growing location because it rarely has frosts. But this year's wet summer has produced perfect growing conditions. "We're almost having two years' worth of growth in one at the moment," says Mr Jones, who learned his craft on trips to Asia.
When the sun does come out it's sweltering and humid. The climatic parallels with somewhere like Darjeeling – 6,000ft up compared to Tregothnan's 246ft – are hard to miss.
Since 1900 the average temperature in the UK has risen by about 1C. It may not seem like much but it has significantly lengthened growing seasons and allowed farmers to farm produce that are far more diverse than our historical staples of cereal and potatoes. But the idea that tea – a commodity we went to war to obtain and protect – could be grown on British shores seems too good to be true.
In some ways it is. There are only a very small number of spots around the UK where tea could thrive. "Tea plants are really quite fickle," says Mr Jones. "They will grow in a sheltered garden. But there's a difference between having a tea bush which is alive and one that is commercially productive."
The hillsides that Tregothnan lies on are about as good as it gets. Sheltered from the Atlantic by the Lizard, it has all the benefits of Cornwall's microclimate without being battered by winter storms or salty water, which is disastrous for tea. It is warm, the soil is acidic and, most importantly, there is lots of rain.
The estate is owned by the family of Lord Falmouth, one of the oldest aristocratic families in Cornwall. His ancestors travelled far and wide with the British Empire and collected all sorts of exotic plants for the gardens back home. While clearing out a garden shed a few years back workers even came across an original Wardian chest, a wooden hut with glass sides which was invented by the botanist Nathanial Bagshaw Ward and was used by Britain to smuggle tea bushes out of China and into India.
Over the years, the gardens back at Tregothnan became famous for exotic flora, particularly its camellias – the same genus of plant as the tea tree. During the late-1990s, while walking through the garden, Mr Jones hit on the idea of growing tea. "I was looking at all these camellias, many of which came from Darjeeling, and they were doing perfectly well," he recalls. "So I thought I'd try to grow tea itself."