Bulb crop · reference page

Spring onions

A slim allium suited to repeated sowing in rows or containers with even moisture and modest root depth.

Scientific name: Allium fistulosum

Editorial guidance without independent agronomic review

Published: 3 August 2026 · Updated: 3 August 2026

Direct sun reference
4 h
Usable root depth
20 cm
First-harvest band
55–100 days

Getting started

Sowing and space

Direct-sow thinly in the final position and thin where stems become crowded.

Allow about 20 cm of usable depth and roughly 6 cm between plants.

Watering reference: moderate and regular. Adjust to rain, heat, wind, growth stage and container volume.

Planting windows by broad profile

These original editorial windows compare thermal groups, not live weather. Check current frost, heat, rainfall and packet directions.

Far north mild and humid

Check the actual site for shelter, drainage, salt exposure and cold-air pockets. Mild regional context is not proof that a tender crop is safe today.

JanFebMarAprMayJunJulAugSepOctNovDec

Sheltered North Island

Compare local frost, soil warmth, rainfall, wind and current water rules. Coast, basin, slope and urban shelter can change conditions over a short distance.

FebMarAprMayJunJulAugSepOct

Eastern North Island

Check root-zone moisture, current restrictions and the live forecast. A dry regional pattern does not rule out frost, storm damage or saturated soil after an event.

FebMarAprMayJunJulAugSep

Keep the seed row moist during emergence.

Lower North Island wet and windy

Select this profile by the growing position rather than a regional label. Secure structures and compare shelter, soil condition and current warnings before planting.

FebMarAprMayJunJulAugSepOct

Northern South Island

Check elevation, distance from the coast, frost pockets and local water settings. Nelson-like shelter and exposed Marlborough sites should not be treated as identical.

FebMarAprMayJunJulAugSepOct

Eastern South Island frost-prone

Confirm current frost risk, soil warmth, wind and irrigation access. Canterbury plains, coastal sites and Central Otago basins require local judgement.

FebMarAprMayAugSepOct

Avoid compacted, saturated growing mix.

Cool wet west and south

Prioritise drainage, safe shelter and a realistic maturity period. West Coast, Southland and Chatham-like exposure still contain substantial local differences.

MarAprMayAugSep

Alpine and high elevation

Treat every month band as a screening signal only. Check frost, access, exposure and the current forecast, and use protection only when it is secure and ventilated.

MarAprSep

Quick bunching types can fit a brief season.

Practical care

  • Sow small batches for continued harvest.
  • Keep weeds from shading narrow leaves.

Points to check

  • Dense sowing can produce weak stems.
  • Check current rules before importing seed or sets.

Provenance and confidence

This rule is an original editorial synthesis and no independent local agronomic review is claimed.

  • New Zealand English home food garden editorial synthesis — version 1

    Global Garden Planner

    Original eight-profile model, Southern Hemisphere planting bands and en-NZ corpus. It remains an editorial draft until independent New Zealand agronomic review is recorded.

    Editorial role: internal synthesis · Rights position: Original project content · Accessed: 3 August 2026

    Open source

  • Common climate and weather terms

    Earth Sciences New Zealand / NIWA

    Supports separating climate, normals, weather and Southern Hemisphere seasons. It does not supply crop thresholds or planting dates.

    Editorial role: fact reference · Rights position: Official scientific page linked and summarized; no glossary text, table, climate normal or derived calendar is reproduced · Accessed: 3 August 2026

    Open source

  • Regional climatologies

    Earth Sciences New Zealand / NIWA

    Supports recognising substantial regional variation in rain, wind, temperature and topography. The eight project profiles and every month band are original editorial synthesis pending review.

    Editorial role: fact reference · Rights position: Official scientific pages linked and paraphrased for broad regional context; no station data, map, grid, chart, value or calendar is copied or transformed · Accessed: 3 August 2026

    Open source

  • Gardening and biosecurity

    Ministry for Primary Industries, New Zealand

    Supports checking unusual pests, unwanted organisms, plant movement and greenwaste handling through current official channels.

    Editorial role: fact reference · Rights position: Official guidance linked and paraphrased; no pest list, reporting form, image, decision tool or substantial wording is reproduced · Accessed: 3 August 2026

    Open source

  • Steps to importing seeds for sowing

    Ministry for Primary Industries, New Zealand

    Supports using traceable local planting material and checking current rules before importing. The project does not determine admissibility.

    Editorial role: fact reference · Rights position: Official procedural page linked and summarized; no standard, species decision, tool, form or import instruction set is reproduced · Accessed: 3 August 2026

    Open source

Use it in context

A month alone cannot resolve cultivar, soil, microclimate or a current extreme.

Use reputable planting material. Use clearly labelled, traceable seed or healthy transplants and check current MPI plus relevant regional biosecurity requirements before importing, ordering or moving plants, seed, soil or growing media.

If a pesticide is considered at all, check current EPA controls, the complete product label and any relevant council restriction; the project does not diagnose a problem or prescribe a treatment.