Green Tea on the Slopes

The Korean tea year begins with its smallest leaves. Hadong County, below Jirisan in South Gyeongsang, sorts its green tea by picking date. Ujeon, very tender tea in the county's words, is gathered before Gogu, the solar term of Grain Rain, around 20 April. Sejak follows until Ipha, around 5 May; jungjak comes about ten days later from larger leaves, and daejak, a coarse tea of tougher leaves, before the end of May.

Each day is a trade. The county's growing guide says yield rises and quality falls with every day the leaf stays on the bush. On sloping gardens, it adds, harvesting is hard and slow, a shortage of hands delays it, and picking at the right time is very difficult.

Those slopes made Boseong and Hadong the great names of Korean green tea, written into heritage registers and the country's first geographical indication. They are also why the crop struggles as its market changes: fewer fields and fewer cups at home, a warming climate, and buyers abroad who want powdered tea in volume, with paperwork to match. The slopes that made Boseong and Hadong famous are the same slopes that make their tea hard to grow at scale.

Slopes, rivers and fog

Tea is a southern crop in Korea because of winter. Hadong's guide puts the best conditions at an annual mean of 13 to 16°C and at least 1,300 millimetres of rain, and says cultivation becomes difficult where the cold reaches −13 to −14°C. Its traditional tea district, Hwagae, lies where the Hwagae stream meets the Seomjin River beneath Jirisan. It is 93 percent mountain, and its wild tea gardens are scattered between rocks at the foot of the slopes, where, the county says, machine work is difficult.

FAO added Hadong's traditional tea agriculture to its Globally Important Agricultural Heritage Systems in 2017, describing 1,200 years of adaptation to barren mountain ground and fields fed with pulbibae, a compost made from oak-forest by-products.

Boseong, in South Jeolla, credits the meeting of maritime and continental climates: an annual mean of 13.4°C, about 1,400 millimetres of rain, wide daily swings and frequent fog, which the county says shades the bushes naturally. It also concedes the cost: tea sown from seed on mountain slopes is awkward and expensive to grow. Its terraces follow the contours, laid out along straw ropes, a system named a national agricultural heritage in 2018.

Fewer fields, fewer cups

At home, the market for hand-picked spring tea has been shrinking from the field up. The agriculture ministry counted 3,800 hectares of tea in 2007, the high point of its series, and 2,551 in 2024. The harvest peaked at 4,758 tonnes of dried leaf in 2019 and was 3,685 tonnes in 2024. Hadong's own figures show 1,042 hectares in 2012 and 665 in 2025.

The cup shrank first. A 2014 Korea Rural Economic Institute (KREI) study found that green tea drinking rose until 2007, fell after a pesticide-residue scare, and fell faster as coffee took its place. More than 90 percent of growers had since switched to environmentally friendly methods, it said, but fewer than half of consumers knew. An earlier KREI report that year blamed slope cultivation for low productivity and found Korean tea dear by other countries' standards.

Jeju works on another scale. In 2024 Jeju's 46 tea farms held 535 hectares, while South Jeolla's 1,468 farms held 1,114 and South Gyeongsang's 1,127 held 827: by Ag Digest's arithmetic, more than 11 hectares per farm on Jeju and under one on the mainland. Amorepacific, owner of the O'Sulloc brand, dates its first Jeju clearing to 1979.

Beyond the domestic cup

Abroad, demand for green tea is growing, mostly in a form Korea's slope gardens were not built to supply. Japan's green tea exports nearly doubled in 2025, to ¥72.1 billion and 12,612 tonnes, by its agriculture ministry's count; powdered tea made up about 70 percent of the volume and 80 percent of the value, and the United States took 40.7 percent. The ministry says tencha, the shaded leaf ground into matcha, sells for about 4.9 times the price of ordinary sencha. China, which grows nearly half the world's tea, supplies more than three-quarters of green tea exports, FAO says.

Korea's exports are small but rising: UN Comtrade data show $4.7 million in 2020 and $8.7 million in 2025, about 259 tonnes, with about two-thirds going to the United States. Hadong County bought 401 tonnes of shaded fresh leaf in 2024, up from 117 tonnes, according to its green tea research institute, Korea Farmers & Fishermen Newspaper reported.

What buyers abroad ask for

Selling there takes more than leaf. The EU applies a default limit of 0.01 mg/kg to any pesticide without a specific residue limit, and Japan's ministry warns that tea meeting Japanese standards can still fail an importer's. Korean growers know the rule: since 2019, Korea's Positive List System has held pesticides without a set limit to 0.01 ppm on every crop.

Organic status travels only by agreement. Korea's equivalence arrangements with the United States (from 2014) and the EU (from 2015) cover processed organic food finished in Korea with at least 95 percent organic ingredients. Japan leans on the same route: 62.8 percent of its 2025 tea exports to the United States went as organic under equivalence.

Then there is the name. Reports from aT, Korea's agri-food trade agency, found Korean green tea sold in the United States mostly through Korean grocers, high-end tea there dominated by Japanese products, and matcha marketing that leans on Japanese origin.

Field note: reading a Korean tea label

• The grade tells you when the leaf was picked, from ujeon before Gogu to daejak in late May.
• A geographical indication ties the tea to its county: Boseong Green Tea is No. 1 (2002), Hadong Green Tea No. 2 (2003), Jeju Green Tea No. 50 (2008).

The open question is what the slopes will be picked for. Shaded leaf for powder sells by the tonne and favours ground that machines can work; hand-picked ujeon and sejak sell by the gram and need steep gardens and hands that are growing scarce. Whether one hillside can do both is what growers are deciding now, bush by bush.

For another crop whose map is being redrawn by climate and land, read The Orchard Moves North.