Natsumidori

Natsumidori is a 1954 landrace selection bred not by a private farmer but by the state itself: an individual tree pulled from the seedling tea garden of the national Tea Experiment Station at Kanaya, Shizuoka, and registered by the Ministry of Agriculture and Forestry as Cha Norin No. 16. It shares its Shizuoka zairai ancestry and its selection method with Yabukita, but not its fame — where Yabukita went on to cover three quarters of the country, Natsumidori was released as one of five green-tea cultivars in a single 1954 registration batch and has since dropped out of nearly every current cultivar list. What survives is an unusually well-documented origin record and a specific, sourced answer to what its name means.

Lineage

• Shizuoka zairai (indigenous) seedling — an individual tree selected from the existing seedling tea garden (実生茶園) of the National Tea Experiment Station at Kanaya, not a controlled cross; carried through station trials under the strain designation 国茶S41号 (Kokucha S-41) before formal registration.

Because it is a landrace selection rather than a bred cross, Natsumidori has no recorded pollen parent. It was registered alongside four other green-tea selections from the same 1954 MAFF batch — Yaeho (Cha Norin No. 17, another Shizuoka zairai selection, this one by Sugiyama Hikosaburo’s household), Asagiri and Kyomidori (Cha Norin Nos. 18 and 19, both Uji zairai selections for gyokuro), and Hatsumidori (Cha Norin No. 20, from Mie-derived seedlings raised in Kagoshima) — but these are batchmates from the same registration cycle, not siblings from a shared parent tree. No cultivar in this collection is recorded as bred from Natsumidori.

History

The National Tea Experiment Station (農林省茶業試験場) was established at Kanaya, in what is now Shimada City, Shizuoka, in 1919, absorbing the tea-breeding work that had previously been scattered across prefectural stations and private growers such as Sugiyama Hikosaburo. In Taisho 9 (1920) — twelve years after Sugiyama picked out the seedling that became Yabukita — researchers at the new station selected an individual tree from its own existing seedling tea garden, itself grown from Shizuoka zairai seed. The line was carried forward under the working strain name Kokucha S-41 (国茶S41号) and fixed as a stable cultivar by Showa 19 (1944), a full 24 years after the original tree was chosen.

Formal registration followed a decade later. The Ministry of Agriculture and Forestry registered Natsumidori as Cha Norin No. 16 in fiscal 1954, one of five newly registered green-tea cultivars and one black-tea cultivar that year, announced in the October 1954 issue of 茶業研究報告 (Tea Research Report) under the title “The New Registered Tea Varieties.” The registration entry describes a mid-season, upright-growing, high-shoot-number sencha type, strong against disease and rated medium for cold tolerance, with cultivation recommended for warm districts west of Shizuoka rather than the colder tea country further north.

The name

The registration bulletin gives the naming rationale directly, and it settles the question this record set out to answer: 「夏茶の葉色がみどり色で品質がよい」 — “the leaf colour of natsu-cha is green, and its quality is good.” Natsu-cha means summer tea: the second and third flush, picked after the prized first flush and generally the pickings where quality falls away fastest. Natsumidori’s name is a claim about that later-season performance, not about when the bush buds in spring.

That claim held up under direct testing. In a 1954-season trial at Kanaya comparing Yabukita, Miyoshi, Tamamidori and Natsumidori side by side, Harada Shigeo and Amma Shun found Natsumidori’s estimated optimal first-flush plucking date fell on 2 May — one day after Yabukita and Miyoshi’s 1 May, and a week ahead of Tamamidori’s 8 May. In other words, Natsumidori buds at essentially the same time as Yabukita, not late; “summer” in its name is not a budding-time claim at all. The same trial found that, unlike Miyoshi and Tamamidori, whose yield increased mainly through the growth of each individual bud, Natsumidori’s yield increased mainly through the number of buds produced — the same pattern as Yabukita — and that its shoots “continued new development of leaves at the harvesting time for a long time,” which the authors judged favourable for holding leaf quality into later pickings. Natsumidori’s tea-shape quality score in that trial declined only slightly across four picking dates (19.0 to 17.5 out of 20), against a much steeper fall for Tamamidori (17.0 to 12.5) over the same window — a controlled result that matches the registration bulletin’s own processed-tea quality table, where Natsumidori’s score dipped from 77.5 in the first flush to 71.0 in the second before recovering to 75.0 in the third, rather than declining flush over flush as is typical.

That documented origin and a formal Cha Norin number — a distinction many landrace selections never received — keep Natsumidori in the breeding record: Takeda Yoshiyuki’s 2007 review of a full century of Japanese tea breeding names it as the first of the six cultivars registered in 1954, and lists it among the 27 nationally bred entries in its table of all 106 cultivars bred nationally, under designated regional trials, by prefectures, and privately since registration began in 1953. It was not, however, found in any English-language vendor or enthusiast cultivar guide checked for this record. It appears to have been formally registered and then, within a few decades, quietly stopped being grown at any scale worth recording.

Characteristics

Natsumidori is a mid-season cultivar: in the 1954 trial that timed it directly against Yabukita, its first-flush plucking date fell just one day later. Growth habit is upright with somewhat strong vigour, and it is a high-shoot-number type — yield increases mainly by producing more buds rather than by each bud growing larger, the same strategy Yabukita uses. In a follow-up study of axillary versus terminal budding, 77% of its buds were axillary, a share between Yabukita’s 71% and Tamamidori’s markedly lopsided 88%. Young leaves are long-oval, small, yellowish-green and soft-textured; mature leaves are long-oval, of medium size, about 0.27 mm thick, yellowish-green and glossy, with a notably wrinkled leaf surface and a wavy, strongly inward-curled margin. A 1977 amino acid survey of green-tea cultivars found Natsumidori among the highest in arginine content in the first flush, alongside Fujimidori and several unnamed breeding lines.

Disease resistance is rated strong and cold hardiness only medium, which is why the 1954 bulletin confines its recommended growing area to warm districts west of Shizuoka rather than the colder tea regions to the north and east. Yield from 14–16-year-old bushes averaged around 450 kg/10a combined across three flushes over 1950–52 (roughly 265 kg first flush, 114 kg second, 71 kg third) — a workable yield, though no source found compares it directly to Yabukita’s own figures from the same era. Chemical analysis of the registration-trial leaf found 4.10% nitrogen and 12.38% tannin (catechins).

As a cup, Natsumidori was assessed as good-quality ordinary sencha, and its one clearly documented distinction is holding that quality across the season rather than in any single striking flavour trait: both the original registration trial and the later comparative study found its second- and third-flush tea scored close to its first-flush tea, where most cultivars — Tamamidori conspicuously among its own trial companions — show a steep falling-off. No source found describes its aroma, colour or taste in more specific terms, and nothing in the record explains why a formally registered, agronomically documented cultivar with a genuinely useful trait fell out of cultivation so thoroughly that no current commercial planting could be located. That disappearance, on the evidence available, is the most notable fact about Natsumidori today.