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Ishikura Green Onion Seeds
Type: Japanese Bunching Onion / Green Onion Botanical Name:Allium fistulosum Plant Type: Biennial grown as annual — Open-Pollinated, Heirloom Days to Maturity: 60 days (baby) to 100–120 days (full shank) Habit: Non-bulbing — long, straight white stalk Flavour: Mild, sweet, tender Harvest Style: Pull whole stalks; sow successively Direct Sow / Transplant: Sow indoors 8–10 weeks before last frost, or direct sow Spacing: 2–3 cm (1 in) apart Sun: Full sun to part shade
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Ishikura Green Onion — The Long, Straight Japanese Bunching Onion
🌍 Where It Grows Best
🇨🇦 Canada: Zones 3–9. Cold-hardy and quick from seed; direct sow in spring or start indoors for an early cut. Tolerates frost and holds well into fall. 🇺🇸 US: Zones 3–10. Day-length neutral — it never bulbs, so it grows the same everywhere. Sow spring through fall in the North, and through the cool season in the South and Southwest. Best for: Stir-fries, ramen and noodle soups, grilling, garnishes, and anyone who wants a long, mild, tender white stem.
Ishikura is the classic Japanese bunching onion — the negi-style green onion grown for its long, perfectly straight, snow-white stalk rather than any bulb. Where most scallions give you a few inches of white before the green takes over, Ishikura runs tall and upright, producing a generous length of mild, tender white shank prized in Japanese and wider Asian cooking. It’s a single-stem type that stands like a miniature leek, and it’s as beautiful in the row as it is useful in the kitchen.
It’s also fast and forgiving. Allium fistulosum germinates in cool soil, grows quickly to a usable size, and shrugs off frost, so you can sow it across a long season and keep cutting tender stalks for months. Because it doesn’t form a bulb, day length is irrelevant — it performs identically whether you garden in the far North or the Deep South. The flavour is clean and mild, sweeter once cooked, and it’s the green onion to reach for whenever a recipe wants real length of white stem: grilled whole, simmered in broth, or sliced raw as a garnish.
Sowing, Growing & Harvesting
Start seed indoors eight to ten weeks before your last frost for the earliest stalks, or direct sow outdoors once the soil can be worked — seedlings tolerate light frost. Sow shallow, about 1 cm (¼–½ in) deep, in rows or a close band. Thin to 2–3 cm (1 in) apart for tender stems, keep the bed evenly moist and weed-free while plants are small, and they’ll grow away steadily. For continuous supply, sow a fresh short row every few weeks through the season.
Harvest any time from baby stage (around 60 days) up to full size at 100–120 days, pulling whole stalks as you need them. The one trick worth knowing is blanching: drawing soil up around the stems as they grow, or planting in a shallow trench and filling in gradually, lengthens and whitens the tender shank — the same technique used for leeks. Ishikura is cold-hardy enough to hold in the garden well into fall, and a mulch extends the harvest further in cold regions.
🥬 How to Get Long, Tender White Shanks
Ishikura’s signature is its long white stem, and the more of it you grow, the more prized it is. The white portion is simply the part shielded from light, so to maximise it, hill soil up around the stems a little at a time as they grow taller, or sow into a shallow trench and gradually fill it in. Don’t bury the green tops — just keep mounding around the lower stem. Two or three hillings over the season give you the long, blanched, exceptionally tender shanks that make Ishikura the favourite for grilling and noodle soups.
New to growing green onions from seed? Our full how to grow green onions guide covers sowing, the cut-and-come-again harvest, and growing green onions in every climate, and you can browse all our green onion & bunching onion seeds for more varieties.
❓ Ishikura Green Onion FAQ
What is Ishikura green onion?
Ishikura is a Japanese bunching onion (Allium fistulosum) grown for its long, straight, mild white stalk. It’s the classic negi-type green onion used throughout Japanese and Asian cooking. Unlike a bulb onion it never forms a bulb, and unlike many scallions it produces an unusually long length of tender white stem.
How is Ishikura different from other green onions?
Ishikura grows as a tall, single, straight stalk rather than a branching clump, and it’s bred to produce a long white shank — closer to a slim leek than a typical scallion. That length of mild white stem is exactly what’s wanted for grilling and for noodle soups, where the whites are simmered whole or in batons.
Does Ishikura form a bulb?
No — like all true bunching onions it never bulbs. It stays as a long white stem with green tops. A useful side effect is that, because bulbing depends on day length and Ishikura doesn’t bulb, it grows equally well at any latitude, North or South.
How do I get the long white stems?
By blanching — shielding the lower stem from light. Hill soil up around the stems a little at a time as they grow, or sow in a shallow trench and fill it in gradually. The covered portion stays white and tender. Just avoid burying the green tops. Two or three hillings over the season produce the long, blanched shanks Ishikura is famous for.
When should I plant Ishikura?
Start indoors eight to ten weeks before your last frost, or direct sow as soon as the soil can be worked in spring. Sow successively every few weeks for a continuous supply. Our planting calendar gives the exact window for your zone.
When should I plant it in the US?
Because it’s day-length neutral, the same method works everywhere: sow spring through late summer across the North, and through the cool season — fall, winter, and spring — in the South and mild West Coast. In the arid Southwest, grow it in the cooler months and give afternoon shade at the height of summer.
How long does Ishikura take to grow?
You can begin pulling tender baby stalks around 60 days from sowing, with full-sized long-shank stems at roughly 100–120 days. Because you can harvest across that whole window, a single sowing supplies green onions over a long period rather than all at once.
Can I grow Ishikura in a container?
Yes. Use a pot at least 20 cm (8 in) deep so the stems have room to lengthen, with good potting mix and consistent watering. You won’t get quite the blanched length you’d manage by hilling in the ground, but a container of Ishikura by the kitchen gives a steady supply of mild, tender green onions.
Will Ishikura survive winter?
It’s cold-hardy and holds in the garden well into fall and early winter, sweetening with frost. In mild regions it overwinters and keeps producing; in cold zones a mulch protects the crowns, and as a bunching onion it can perennialize, resprouting in spring. For the longest, best-quality stalks, though, most growers treat it as a spring-to-fall crop.
What does Ishikura taste like?
Mild, clean, and gently sweet, with the long white shank being the most delicate part. Raw, it has a fresh, crisp onion bite; cooked, it turns soft, sweet, and almost silky — which is why the whites are so good grilled or simmered in broth. It’s noticeably milder than a mature bulb onion.
How do I use Ishikura in the kitchen?
It’s a staple of Asian cooking. Simmer the white shanks in ramen and other noodle soups, grill them whole until soft and sweet, slice them into stir-fries and fried rice, or use them raw as a garnish. The tender white parts shine when cooked, while the green tops make a bright finishing garnish — use both.
Is Ishikura the same as a leek?
No, though they look similar when blanched. Ishikura is a bunching onion (Allium fistulosum) with slimmer stems and a milder, more onion-like flavour, while leeks (Allium ampeloprasum) are larger and take a longer season. Ishikura is faster and more delicate; a leek is a heftier, slower cooking vegetable.
Are green onions good for you?
Yes — they’re low in calories and provide vitamins K, C, and A, folate, and the beneficial sulphur compounds found across the onion family. The green tops are especially nutrient-rich. They add a lot of flavour for very little, making them an easy, healthy addition to almost any savoury dish.
Will Ishikura regrow after cutting?
If you cut the green tops and leave the white base and roots in the ground, the plant will push new growth and you can harvest again. For the long blanched shanks Ishikura is grown for, though, most gardeners pull whole stalks and sow successively so there’s always a fresh batch lengthening.
What pests or problems should I watch for?
Ishikura is largely trouble-free. The usual onion-family pests — onion maggot, thrips, and onion rust — are kept rare by crop rotation, tidy beds, and good airflow. The plant’s strong scent also helps deter pests from nearby crops, which makes onions valued companions in the vegetable garden.
Can I save seed from Ishikura?
Yes — it’s an open-pollinated variety, so it comes true from saved seed. Leave a few plants to flower in their second year, let the round seed heads dry on the plant, and collect the small black seeds. Onion seed is short-lived, so store it cool and dry and sow within a year or two for the best germination.
Can I freeze Ishikura green onions?
Yes. Slice and freeze them — frozen green onions hold their flavour well for cooked dishes like soups, stir-fries, and fillings, though they lose their crisp texture for raw use. Fresh, they keep about a week in the fridge with the roots in a little water or wrapped in a damp towel.
Long, Mild White Stalks for the Kitchen
Ishikura green onion seeds on Amazon — ships to Canada and the US.
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