When to plant onions in zone 3
In USDA zone 3, the last spring frost usually falls between May 5 and May 31. Start onions indoors around Feb 26 to Mar 29. Plant them out around May 10 to Jun 4. Expect to harvest around Sep 9 to Oct 16.
Zone 3 dates for onions
| Start seeds indoors | Feb 26 to Mar 29 |
|---|---|
| Plant outside | May 10 to Jun 4 |
| Harvest | Sep 9 to Oct 16 |
| Typical last spring frost | May 5 to May 31 |
| Typical first fall frost | around Sep 15 |
USDA zones measure winter cold, not frost dates, so these are typical dates for the zone. Towns in the same zone can be weeks apart.
Get dates for onions in your exact town, not just your zone.
Get my dates free →How to grow onions
Plant once, season everything all year. Read the full onions growing guide: spacing, sun and soil, step-by-step care, problems and the best varieties.