Plant Onions in Zone 5b
Seed-starting, transplant & harvest dates for USDA Zone 5b
Start indoors
Feb 14
Transplant
Apr 11
Harvest (~100d)
Jul 20
In Zone 5b, the average last spring frost is around April. 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
Apr 25
First fall frost
Oct 8
Growing season
166 days
Full Onions grow guide → · All crops for Zone 5b →
Frequently asked questions
When should I start onions in Zone 5b?
Start onions seeds indoors around Feb 14 (Zone 5b).
Can I direct sow onions in Zone 5b?
Onions is best started indoors and transplanted in Zone 5b rather than direct sown.