Tregothnan

Tregothnan, tucked into a sheltered valley on the banks of the River Fal in Cornwall, succeeded in 1999 in growing the first tea plant cultivated in Cornwall, and the first English tea it produced was sold in November 2005 — to Fortnum & Mason, the London department store, giving the country's first homegrown tea an unusually credentialed retail debut. The estate describes itself as home to the largest tea gardens in Europe.

Tregothnan positions itself as the first English tea company to build a full range — black tea, green tea and herbal infusions — grown on British soil, and it blends its own Cornish leaves with premium leaves from Assam and Darjeeling rather than offering the homegrown crop only as a novelty in isolation. The estate is open to visitors for tea and orchard tours and tea masterclasses, letting a customer see the plants a British-grown tea actually came from, an experience no other tea house on this list can offer.

For a country with no prior tea-growing tradition, Tregothnan's 1999 planting and 2005 Fortnum's debut are still the reference points anyone selling English-grown tea has to answer to.