When to plant onion in Auckland
Onion is cold-hardy, so every date keys off Auckland's frost dates.
Step 1 · Sow
Direct sow outdoors
Jul 12 – Aug 2
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Oct 10 – Oct 30
Picking runs until conditions turn against the crop.
Window
Days to maturity
90 – 110 d
From sowing to first pick.
Common questions
When can I sow onion outdoors in Auckland?
Direct-sow around mid July (Jul 12–Aug 2) in Auckland, based on its local frost dates. Confidence 44%.
When will onion be ready to harvest in Auckland?
Expect to harvest from around early October (Oct 10–Oct 30) in Auckland, based on its local frost dates. Confidence 40%.
How long is the growing season in Auckland?
Auckland has roughly 365 frost-free days, which is enough time to grow onion to maturity outdoors.
The rule of thumb
Sow onion as soon as the soil is workable — it tolerates cool weather and light frost. Every date on this page is derived from that rule and Auckland's frost dates.
Confidence 45/100 · Curated · based on NASA POWER (modeled) 1991–2020 · frost dates are probabilities, not guarantees.