The four that dominate, and what each is for
TeaHQ's own reading of well-attested general knowledge, with no single source behind it.
CHINA produces by far the most tea in the world and exports a modest fraction of it. Most Chinese tea is drunk in China, across every category — green above all, then dark, oolong, black, white and yellow. A world production table therefore tells you very little about what reaches a Western shelf. INDIA is second, and the same pattern holds harder: India drinks the large majority of what it grows, almost all of it as strong milky chai made from CTC leaf. Assam and the smaller Darjeeling and Nilgiri districts are what an export market knows; they are not what India drinks. KENYA is the largest EXPORTER of black tea, and almost none of what it produces stays home in the form Western drinkers would recognise. It is overwhelmingly CTC, sold in bulk at the Mombasa auction, and it is inside a very large share of the blended tea bags sold in Britain and Europe without appearing on the front of any of them. SRI LANKA is the fourth of the big producers and the most export-oriented of them, with a national brand — Ceylon — that has survived the country's renaming by half a century.
Producing a lot and exporting a lot are different facts
This is the single most useful correction on the page. Rankings circulate without saying which question they answer, and three different rankings exist: BY PRODUCTION, China leads by a very wide margin. BY EXPORT VOLUME, the order changes completely — Kenya is at or near the top, because it grows for export by design. BY CONSUMPTION PER HEAD, neither list survives. Turkey is consistently at or near the top and grows nearly all of its own; Ireland and the United Kingdom are high and grow none; Morocco is high and grows none. A country can be enormous in one of these and invisible in the others, and a claim about "the biggest tea country" is meaningless without saying which.
The second tier, and why it is where the interesting tea is
TeaHQ's own reading of well-attested general knowledge, with no single source behind it.
TAIWAN produces a small volume and an outsized share of the world's best oolong. Its high-mountain districts are a speciality market rather than a commodity one. JAPAN grows almost entirely for its own domestic market — steamed green tea, plus the tencha that becomes matcha — and exports comparatively little, which is a substantial part of why good Japanese tea is expensive abroad. VIETNAM is a large producer by volume, much of it sold as unbranded bulk into blends, and has its own distinctive high-mountain and shan tuyet material that rarely leaves. NEPAL grows in conditions continuous with Darjeeling's, at competitive cost, and its material has become a significant presence in a market that often does not name it. INDONESIA, ARGENTINA, TURKEY, IRAN, BANGLADESH, MALAWI, TANZANIA, UGANDA, RWANDA and BURUNDI all produce meaningfully. Argentina is worth a specific note: it is a large producer whose crop goes largely into American iced tea, which is why a country nobody associates with tea is in a great many American glasses.
Where tea can be grown, in one sentence
The plant wants warmth, high rainfall spread across the year, acidic well-drained soil and no hard freeze, which puts commercial tea in a belt running roughly from 40°N to 30°S with a strong bias toward monsoon Asia and equatorial East Africa. That envelope is why the map looks as it does, and it is also why the edges of it are interesting: Georgia, Turkey's Black Sea coast, Cornwall, the Azores, Hawaii, Scotland and Washington State are all at or past the margin, growing small volumes at costs that only a speciality price supports.
What a country name on a packet does and does not tell you
Very little on its own, and less than a region name. "Product of China" spans green, white, oolong, black and dark tea from a dozen provinces with nothing in common. "Ceylon" spans elevations that produce genuinely different teas. Blends carrying several origins are usually not required to say so in any detail. The useful ladder runs country, then region, then district, then garden or producer, and each step down is worth more than the one above it. A packet that names a garden and a harvest is telling you something; a packet that names a country is telling you where a customs form was stamped.