Plant Onions in Zone 9a
Seed-starting, transplant & harvest dates for USDA Zone 9a
Start indoors
Dec 21
Transplant
Feb 15
Harvest (~100d)
May 26
In Zone 9a, the average last spring frost is around March. 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
Mar 1
First fall frost
Nov 30
Growing season
274 days
Full Onions grow guide → · All crops for Zone 9a →
Frequently asked questions
When should I start onions in Zone 9a?
Start onions seeds indoors around Dec 21 (Zone 9a).
Can I direct sow onions in Zone 9a?
Onions is best started indoors and transplanted in Zone 9a rather than direct sown.