Plant Onions in Zone 3a
Seed-starting, transplant & harvest dates for USDA Zone 3a
Start indoors
Mar 6
Transplant
May 1
Harvest (~100d)
Aug 9
In Zone 3a, the average last spring frost is around May. Onions is a hardy crop, so give it a head start indoors about 10 weeks before that, then move it out after frost danger passes.
Last spring frost
May 15
First fall frost
Sep 15
Growing season
123 days
Full Onions grow guide → · All crops for Zone 3a →
Frequently asked questions
When should I start onions in Zone 3a?
Start onions seeds indoors around Mar 6 (Zone 3a).
Can I direct sow onions in Zone 3a?
Onions is best started indoors and transplanted in Zone 3a rather than direct sown.