How to Grow Onions: When to Plant Onions in the US
Updated October 2026
The one rule that makes or breaks Florida onions: plant short-day varieties. Long-day types simply won't bulb here.
What it looks like as it grows
🌱 Plant profile: Onion, with sowing times for your region, companion plants and common pests.
When to Plant Onions in Your Region
When to plant onions depends on day length as much as frost. Florida and the Gulf South grow short-day onions planted in fall and early winter, so they bulb before the long days of late spring, while the North plants in spring. These are the planting months for each of our 18 regions, with each region's frost window. Each region links to its full vegetable planting calendar, and the Onion plant page shows the calendar for any region you pick.
| Region | Plant | Frost window and local note |
|---|---|---|
| North Florida | September to January | February 15 to December 5 |
| Central Florida | September to January | Effectively frost free |
| South Florida | October to December | Effectively frost free |
| Gulf South | September to January | February 25 to December 1 |
| Desert Southwest | October to November | February 5 to December 5 |
| Texas | January and October to November | March 1 to November 28 |
| Southern California | January to February and September to November | Effectively frost free |
| Mid-South | February to March and September to October | April 10 to October 25Plant sets from mid February to March, or sets and transplants from mid September to mid October for an overwintered crop. |
| Pacific Northwest | February to April and August to September | March 25 to November 15Plant sets or transplants in early spring, or sow overwintering varieties in August or September so the plants are small going into winter and do not bolt. |
| Northeast & New England | April to May | May 10 to October 15 |
| Mid-Atlantic | March to April | April 15 to October 25Plant sets, seed or transplants from mid March to April for bulbs by midsummer. |
| Midwest & Great Lakes | April to May | April 30 to October 15 |
| Upper Midwest & Northern Plains | May to June | May 15 to September 25 |
| Mountain West | April to May | May 5 to September 30 |
| Southern Plains | March to April | April 10 to October 30Plant sets, seed or transplants from mid March to April for bulbs by midsummer. |
| Northern California & Central Valley | August and October to January | February 28 to November 17Sow seed in August, set out transplants in October, or plant sets from October to January. |
| Hawaii | October to March | Effectively frost free |
| Alaska | May to June | May 15 to September 10 |
North Florida, Central Florida and the Gulf South plant onions between September and January. The Northeast and New England, the Midwest and the Mountain West plant onions in April and May. The Mid-Atlantic and the Southern Plains plant onions in March and April. The Upper Midwest and Alaska plant onions in May and June.
When to plant in Florida
| Region | Plant sets/transplants |
|---|---|
| North Florida | Oct to Nov |
| Central Florida | Oct to Dec |
| South Florida | Nov to Dec |
Varieties
- 'Granex' (the Vidalia type): sweet, the Southern short-day standard.
- 'Texas Early Grano': large, mild, short-day.
- 'Red Creole': pungent and stores better in the South.
How to grow them
- Plant transplants or sets in fall; they grow leaves through winter and bulb as days lengthen in spring.
- Full sun, rich soil, steady water and regular light feeding for big bulbs.
- Keep weeded; onions compete poorly.
Harvest
When the tops yellow and fall over in late spring, lift the bulbs and cure them in a dry, airy, shaded spot for a couple of weeks before storing.
Source: UF/IFAS Florida Vegetable Gardening Guide (SP 103).
What to Plant with Onions
Our companion data lists these plants as good neighbors for onions, and these to keep apart. The lists read both ways, so a plant that names onions as a companion appears here too. The full companion planting chart for vegetables has the same lists for 55 crops and prints on one sheet.
- Good companions for onions: Beet, Brassicas, Carrot, Chamomile, Dill, Lettuce, Strawberry, Swiss Chard, Turnip.
- Keep onions apart from: Asparagus, Beans, Fava Beans, Peas, Snow Peas.
Onions at a glance
The planting figures for onion from our plant data, converted to inches and Fahrenheit.
| Planting depth | 1/2 inch |
|---|---|
| Spacing | 4 inches |
| Days to come up | About 12 days |
| Soil temperature for sprouting | 50 to 77°F |
| Days to harvest | About 180 days |
| Frost | Half-hardy |
| Container | At least 12 inches (partial success) |
Planting onion sets, transplants and seed
Onions can be grown from sets, transplants or seed. Plant them shallow, about 1/2 inch deep, so the bulb sits near the surface, and about 4 inches apart. Our plant data gives seed a soil temperature range of 50 to 77°F and about 12 days to emerge. Keep the bed weed free, because onions hate competition, water steadily while the tops grow, and ease off as the bulbs swell. See how to grow onions from sets.
Growing onions in containers
Onions can grow in a container at least 12 inches across, though our plant data rates them only a partial success in pots. For a quicker container crop, try green onions in pots.
How long do onions take to grow?
Onions are a long crop. Our plant data allows about 180 days, around six months, from planting to harvest. Lift them once the tops yellow and flop over at the neck, loosen the soil with a fork, and cure the bulbs in a dry, airy place before storing. If plants send up a flower stalk early, see why onions bolt.
Frequently asked questions
When should I plant onions?
North Florida, Central Florida and the Gulf South plant onions between September and January. The Northeast and New England, the Midwest and the Mountain West plant onions in April and May. The Mid-Atlantic and the Southern Plains plant onions in March and April. The Upper Midwest and Alaska plant onions in May and June. The table on this page lists all 18 regions with their months.
How long do onions take to grow?
Our plant data allows about 180 days, around six months, from planting to harvest.
Can I plant onions in October?
Yes, in 10 of our 18 regions: North Florida, Central Florida, South Florida, the Gulf South, the Desert Southwest, Texas, Southern California, the Mid-South, Northern California and Hawaii. Everywhere else our calendar has no October planting for onions; the table on this page shows each region's months.
What kind of onion should I grow in Florida?
Short-day onions. Florida needs short-day types, planted as transplants or sets in fall so they bulb before the long days of late spring; northern long-day types will not bulb there. Granex, the Vidalia type, and Red Creole are the varieties in our data.
When to plant in your region
Pick your region to see the planting months for onions where you garden.
See also: Onions in the plant library →
Related guides
See what to plant this month
Pick your region for a month-by-month calendar tuned to your climate.
Find your region →Plant profile
The onion profile has sowing times for your region, companion plants and common pests.