Plant Onions in Zone 10a
Seed-starting, transplant & harvest dates for USDA Zone 10a
Start indoors
Nov 22
Transplant
Jan 17
Harvest (~100d)
Apr 27
In Zone 10a, the average last spring frost is around January. 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
Jan 31
First fall frost
Dec 20
Growing season
323 days
Full Onions grow guide → · All crops for Zone 10a →
Frequently asked questions
When should I start onions in Zone 10a?
Start onions seeds indoors around Nov 22 (Zone 10a).
Can I direct sow onions in Zone 10a?
Onions is best started indoors and transplanted in Zone 10a rather than direct sown.