Allium fistulosum

Sowing and cultivation guidance

Allium fistulosum seeds prefer full sun to light shade and a fertile, well-drained soil kept evenly moist. Start under cover before the last frost, then transplant once seedlings are sturdy; or direct sow when the soil is workable. In mild climates, autumn sowing can overwinter for an early crop. Sow thinly for close bunching or give a little extra room for thicker stems, maintaining airflow to reduce disease. Follow packet guidance for sowing depth and spacing. Keep beds weed-free, mulch to conserve moisture, and avoid waterlogging. Plants form compact, upright clumps; harvest progressively, cutting at the base to encourage new shoots.

• Harden off seedlings gradually and plant out after last frost; keep moisture even without saturating the soil.
• For bunching growth, sow thickly and thin in stages to maintain airflow; wider spacing yields thicker stems.
• Container suitable: grows well in deep pots with free-draining mix and consistent watering.
• Pollinator friendly: if allowed to flower, the umbels may attract visiting insects.
• Edible: cultivated for mild, onion-like leaves and stems; regular harvesting encourages new growth.

How do you grow bunching onions (Allium fistulosum) from seed?

Sow Allium fistulosum seeds in trays, modules, or directly in the bed, keeping the medium evenly moist and free-draining. For modules, multi-sow 4–8 seeds per cell to plant out as ready-made clumps; for rows, sow thinly. Maintain gentle warmth and steady moisture for germination in about 7–21 days, then grow on in bright light. Harden off before planting out. These onions stay non-bulbing and are harvested for their tender stems and leaves. Provide full sun to light shade, fertile soil, and consistent moisture; weed lightly to avoid root disturbance and keep airflow around plants.

When should I sow Allium fistulosum?

Sow under cover a few weeks before the last expected frost to gain an early start, then transplant once the soil is workable. Direct sow outdoors when the ground can be prepared without clods or smearing. In mild climates, autumn sowing is possible for overwintering plants and early harvests the following season. Successive small sowings after the last frost help stagger harvests. In regions with short, cool seasons, raising transplants under cover can be more reliable than waiting for warm soil.

What soil and sun are best for Welsh onions?

Welsh onions prefer full sun to light shade and a well-drained, fertile soil that holds consistent moisture without becoming waterlogged. Work in mature compost before sowing or planting to boost structure and nutrition, and avoid heavy, compacted spots where drainage is slow. A light mulch helps regulate moisture and limits weed competition around the shallow roots. They interplant well between slower crops and with leafy greens or carrots thanks to their slim, upright habit, provided there is adequate spacing for airflow.

How deep and how far apart should I sow bunching onion seed?

Sow seeds shallowly, about 0.5–1 cm deep, covering lightly and firming gently for good seed-to-soil contact. For direct rows aimed at scallions, sow thinly and thin or harvest to about 2–5 cm between plants, with 15–25 cm between rows; this close spacing supports continuous bunching while still allowing airflow. For module-sown clumps, plant each multi-sown plug 10–15 cm apart. The plants are compact and upright, so you can plant densely for slender stems or give a little more room for thicker shanks; adjust to your harvest preference and follow packet guidance.

Can you grow green onions in containers?

Yes, bunching onions are well-suited to containers. Choose a pot at least 15–20 cm deep with ample drainage, filled with a high-quality, free-draining mix enriched with compost. Multi-sow several seeds per pocket or plant module-grown clumps 5–8 cm apart for a productive mini-patch. Keep the pot in full sun, water consistently so the mix never fully dries, and feed lightly if growth slows. In cold spells, protect containers from hard freezes by moving them to a sheltered spot or insulating the pot to safeguard roots.

How do I harvest and overwinter bunching onions, and are they perennial?

Bunching onions are typically perennial, forming clumps that can be cut and will regrow; harvest when stems reach pencil thickness by pulling individual plants, lifting whole clumps, or cutting outer shoots and leaving centres to resprout. For continuous production, leave some plants in place and divide crowded clumps every couple of years. Overwinter in the ground by mulching after the last harvest to buffer cold and temperature swings; in mild climates, autumn-sown plants often overwinter and resume growth early. Allowing some plants to flower attracts pollinators and may lead to light self-seeding; remove spent blooms if you prefer to limit volunteers.

Information on this site is compiled from horticultural references and supplier specifications. Guidance is general and intended for typical garden conditions; timing and techniques may vary with microclimate, soil type, drainage, and seasonal patterns (e.g., after last frost or when soil is workable). Product pages provide precise details—such as sowing depth, spacing, germination temperature, and days to maturity—reflecting the characteristics of the specific seed or plant offered.

Cultivation notes for bunching onions

Allium fistulosum seeds suit cool-season cultivation and steady succession sowing. Start under cover when soil is workable, or direct sow after last frost; in mild climates, autumn sowing may be possible. Choose a sunny, free‑draining bed enriched with organic matter, keeping moisture even but not waterlogged. Sow thinly and thin seedlings to maintain airflow; wider rows support easy weeding and consistent growth. Plants form perennial-style clumps that can be divided, and harvests are flexible: snip greens as needed or lift full bunches. Mulch helps regulate soil temperature and reduce weeds through dry or cold spells. Rotate away from other alliums to limit disease carryover, and remove flower stems to encourage continued leaf production. Aphids and thrips can be deterred by good spacing and steady watering, while a light feed supports regrowth after cutting. Further cultivation notes and complementary seed lines: SeedsChoice.