When to plant onion in St. Petersburg
Onion is cold-hardy, so every date keys off St. Petersburg's frost dates.
Step 1 · Sow
Direct sow outdoors
Jan 7 – Jan 28
Sow straight into warm, workable soil.
Step 2 · Harvest
Harvest window
Apr 7 – Apr 27
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 St. Petersburg?
Direct-sow around early January (Jan 7–Jan 28) in St. Petersburg, based on its local frost dates. Confidence 77%.
When will onion be ready to harvest in St. Petersburg?
Expect to harvest from around early April (Apr 7–Apr 27) in St. Petersburg, based on its local frost dates. Confidence 71%.
How long is the growing season in St. Petersburg?
St. Petersburg 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 St. Petersburg's frost dates.
Confidence 79/100 · Curated · based on NOAA GHCN-Daily 1991–2020 normal · frost dates are probabilities, not guarantees.