When to plant onions in Florida
Florida’s average last spring frost is February 12, and the first fall frost typically arrives around December 10 — about 301 frost-free days (USDA zones 8a, 8b, 9a, 9b, 10a, 10b, 11a). Onion needs 90–120 days to mature, which fits comfortably within Florida's growing season.
Florida covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant onions in Florida: the short answer
For a spring planting, plant out Jan 15 – Feb 1, with seeds started indoors Nov 27 – Dec 11. Seeds germinate in soil from 40 to 90°F.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow onions in Florida, step by step
- Start seeds indoors (Nov 27 – Dec 11). Sow seeds ½ inch deep in seed-starting mix under bright light. They take 7-14 days to sprout, fastest in soil around 70°F. Harden seedlings off for a week before they go outside.
- Prepare the bed. They need at least six to eight hours of direct sun a day and loose soil at least 12 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Plant out (Jan 15 – Feb 1). Space plants about 4 inches apart in rows 12 inches apart. It handles frost well, so it can go out before the last frost date. As a cool-season crop it does best before summer heat arrives in Florida.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: onion maggot, onion thrips. Diseases and disorders: downy mildew, white rot, neck rot, purple blotch.
- Harvest (from about Apr 22 – May 22). Onion takes 90-120 days to reach harvest. Match the day-length type to your latitude: long-day onions for the north, short-day for the south, day-neutral anywhere. Bulbing is triggered by day length, not calendar date.
Figures come from our crop data; dates use Florida’s average frost dates. More in the full onion growing guide.
Onion planting dates by USDA zone in Florida
Florida spans USDA zones 8a, 8b, 9a, 9b, 10a, 10b, 11a. Colder zones, usually higher or further inland, have a later last spring frost and an earlier first fall frost than the state average, so the onion dates shift with them.
When to plant onions in nearby states
| State | Last frost | Plant out |
|---|---|---|
| Florida (this page) | February 12 | Jan 15 – Feb 1 |
| Alabama | March 25 | Feb 25 – Mar 14 |
| Mississippi | March 20 | Feb 20 – Mar 9 |
| Louisiana | March 5 | Feb 5 – Feb 22 |
| Arkansas | April 3 | Mar 6 – Mar 23 |
Questions gardeners in Florida ask
When is the best time to plant onions in Florida?
Plant onion transplants outdoors in Florida between January 15 and February 1. That timing is set by Florida's average last spring frost of February 12; Florida spans several climates, so cooler and higher parts of the state run later.
When should I start onion seeds indoors in Florida?
Start seeds indoors between November 27 and December 11, about 10 weeks before the last frost, so the seedlings are ready to plant out from January 15.
When will onions planted in Florida be ready to harvest?
Planted on time, onions are usually ready from about April 22 to May 22, 90-120 days after transplanting.
When is the last frost in Florida?
On average around February 12, with the first fall frost around December 10 - about 301 frost-free days. Your town may differ by two weeks or more.