Okumidori, the late green.

I learned the cultivars the way most farm children do, by walking the rows in April. The Yabukita rows wake first. You see the first soft shoots and the whole family starts counting days. The Okumidori rows stay quiet. Tight, dark, patient. For more than a week they look as if nothing is happening. Then they come all at once.

That patience was not an accident. Someone wanted it, wrote it down, and spent twenty one years proving it. This is the story of Okumidori told from those records: the 1975 registration paper from Japan's national tea research station, the prefectural trial reports that followed, and a few things that have only been learned since.

The ten day problem

To understand why Okumidori exists, picture Japanese tea in the early 1970s. Yabukita, a selection made in Shizuoka and registered in 1953, had become so dominant that the registration paper puts it at about 80 percent of all cultivar tea fields. Yabukita is a wonderful tea. But when most of a country's bushes are the same plant, they all wake on the same days, and the whole first flush has to be picked, steamed and rolled in one short rush.

The paper names the problem plainly: a growing shortage of labour, and a strong demand for a late cultivar that could spread the harvest. An earlier attempt, Kanayamidori, registered in 1970, was only middle late. Okumidori was described in the paper as 「期待の晩生品種」, the late cultivar everyone was waiting for.

From one cross to a name

The work happened at the Ministry of Agriculture and Forestry tea research station in Kanaya, Shizuoka. Until 1961 it was called the tea division of the Tokai Kinki Agricultural Experiment Station. Every stage of the breeding, from the first flower to the last trial plot, was done there.

Source: the 1975 registration paper and the Kyoto Prefectural Tea Research Institute's history of breeding.

Twenty one years from flower to name is not unusual for tea. A 2026 review of Japanese tea breeding puts the typical cycle at about 25 years. A tea bush is slow to judge. You have to see how it handles frost, drought, disease and a dozen harvests before you can trust it.

The people who made it

The registration paper lists everyone who worked on the line at each stage. I think they deserve to be named, so here they are.

From Table 1 of the 1975 paper. Names as printed; we give readings only where we could confirm them.

Watanabe Akira is the thread through all of it. He was there at the cross in 1953, and his name is on the paper that reported the finished cultivar twenty two years later.

What the name means

おくみどり is written in hiragana, which is normal for Japanese tea cultivars. みどり (midori) is green. The paper itself never explains the name. Read plainly, おく (oku) is the sound of 奥手 or 晩生 (okute), the everyday Japanese word for a variety that ripens late. That reading fits the whole purpose of the tea. But the breeders did not write it down, so we treat it as a reading and not a fact.

The plant, measured

Here is what the breeders measured on the mature bushes at Kanaya, side by side with Yabukita. These are the numbers that later made Okumidori interesting for matcha, even though nobody was thinking about matcha yet.

Two things in that table matter for what came later. The leaf is smaller and thinner than Yabukita's, and it has more gloss. And the bush is a shoot number type (芽数型): it carries many shoots rather than a few heavy ones. In the paper's shear picked first flush, Okumidori had 187 shoots in a 30 cm square against Yabukita's 165.

A spring, in the 1970s plots

The breeders recorded budbreak and plucking dates for three years, hand picked and shear picked, next to Yabukita and two other cultivars. Move the slider through spring to watch the cultivars wake one after another. You can switch between the home station in Shizuoka and the trial plot at the Kyoto tea research station.

Yield, the reason farms planted it

A late tea that cropped poorly would never have spread. Okumidori did the opposite. Across eleven years of strain trials at Kanaya, its total for the first three flushes beat Yabukita in eleven of twelve comparisons and tied in the other.

The regional trials told the same story, and the Kyoto result is the one I always point to. At the Kyoto Prefectural Tea Research Institute, on five year old bushes in 1973, hand picked Okumidori gave 629 kg of fresh leaf per 10 are (1,000 square metres) over two flushes. Yabukita gave 320. Almost double, in the place that would later make it famous.

Cold, frost and the things to watch

Lateness is also protection. A bush that wakes later is less likely to have soft new shoots out when a late frost comes through in April. The paper rated Okumidori's resistance to winter leaf damage the same as Yabukita, tested by holding cut branches at minus 15°C for two hours, and found it dropped fewer leaves in winter. It recommended Okumidori for mountain and valley gardens where frost damage is common.

It was not perfect, and the paper says so. In parts of Kyushu, young bushes in their first and second winters could suffer trunk splitting from frost, so growers were told to protect them while young. Mie Prefecture's grower notes say much the same today: strong and easy to grow, but a little weak to bark damage (さめ肌) and trunk splits (幹割れ). They also note that if it is picked late, white stems can show in the finished tea.

In the cup, by the 1970s judges

Okumidori was registered as a sencha cultivar, and the trial teas were sencha. The judges scored appearance, colour, aroma, liquor colour and taste, 20 points each. Over three tasting years at Kanaya its first flush scored between 98 and 105 percent of Yabukita, a dead heat. In the second and third flush it often came out ahead.

The chemistry was just as close. In the 1973 first flush, hand picked one bud and three leaves, the two cultivars were almost identical:

Then there is Kyoto again. In the 1973 regional tasting, the Kyoto panel scored Okumidori's first flush aroma 19.0 out of 20 against Yabukita's 16.0, and its colour 18.5 against 17.0. In the second flush the gap was wider: 91 points to 78.

How a sencha cultivar became a matcha cultivar

Nothing in the registration paper mentions tencha or matcha. Okumidori was bred so sencha farms could spread their harvest. Its second life came from the shaded tea gardens of Uji, and from what happens to its leaf under cover.

Tencha (碾茶) is grown under shade for about three weeks before picking, then steamed and dried flat without rolling, and that leaf is what gets stone milled into matcha. Under shade, a tea bush pushes chlorophyll into its leaves to catch the little light it gets. The research stations have spent the last thirty years testing which cultivars respond best. Okumidori keeps coming out near the top.

Summaries of published prefectural research results. Each was a single study in one place; farm, soil and season all change the outcome.

That thin leaf is the key. It is the same 0.30 mm leaf the breeders measured in the 1960s. Thin leaves full of chlorophyll make bright, deep green tencha. They also bruise and fold easily, which is why Kyoto's researchers warn tencha makers not to steam Okumidori too long. Every gift comes with its own care instructions.

Where Okumidori stands today

Fifty years on, Okumidori is the fourth most planted tea cultivar in Japan. A 2026 review in Breeding Science, using Ministry of Agriculture data for 2025, puts it at 3.4 percent of the national tea area.

In Kyoto, its weight is much greater than that national figure. A NARO research report, citing Kyoto data from 2016, lists the five cultivars with the largest tencha area in Kyoto as Yabukita, Okumidori, Samidori, Sayamakaori and Gokō. The two cultivars bred specifically for tencha, Samidori and Gokō, made up about 13 percent between them. So the second most planted tencha cultivar in the home of matcha is a late sencha tea from Shizuoka.

A question about its father

Here is something you will not find on a matcha tin. The registration paper records the cross as Yabukita × Shizuoka zairai No. 16. In 2021, a team led by Nakao Kubo at Kyoto Prefectural University tested 79 Japanese tea cultivars with DNA markers to check their family trees. In their paper they note, citing an earlier DNA study by Matsumoto (2006), that Okumidori's father does not seem to be Shizuoka zairai No. 16.

That does not change the tea. Every Okumidori bush is still a cutting of the one seedling the breeders chose in 1960. It may mean a stray grain of pollen in October 1953, or a slip in the records. Nobody can say now. The note concerns the father only, and most references, including the 2026 review, still list the original pedigree. We think the honest answer is that the father is an open question.

Okumidori, Samidori and Yame

Two comparisons come up again and again in searches, so let us settle them.

In the bowl, the difference people usually describe is that Okumidori leans deep green, smooth and mellow, while Samidori is prized in Kyoto for a bright, clear colour and a fine aroma and flavour. Both are classic Uji tencha cultivars. Neither is better. They are different plants doing different jobs.

Okumidori vs Yame is a different kind of question. Yame (八女) is not a cultivar. It is a tea region in Fukuoka Prefecture, famous for gyokuro. Yame farms grow several cultivars, so a Yame matcha could be Okumidori or something else entirely. Comparing Okumidori with Yame is comparing a plant with a place. The useful questions are which cultivar, from which region, and how it was shaded and milled.

Single cultivar Okumidori

Most matcha is a blend of cultivars, because blending keeps colour and taste steady from year to year. A single cultivar matcha is made from one cultivar only, so you taste that plant's character clearly. Okumidori is one of the most common single cultivar matchas for a good reason: it is the cultivar that most reliably gives that deep green colour and soft, rounded taste.

Single cultivar is a style, not a grade. A grade describes the leaf, the harvest and the milling. A single cultivar label tells you which plant it came from. You want to know both.

Our Kyoto Uji Ceremonial Matcha is single cultivar Okumidori from Uji, stone milled, and it is a true emerald in the pouch. If you want to taste what this whole story leads to, whisk it straight. Start with 2 g, about one level teaspoon, and 70 ml of water at about 75 to 80°C. Our whisking guide walks you through it.

日本語で読む · Read it in Japanese

This part is for our readers in Japan, and for anyone learning Japanese through tea. Choose Japanese, English, or both side by side.

A small glossary for reading Japanese tea research.