If you’re a gardener in the Sunshine State, knowing when to plant onions in Florida is the first step to a successful harvest. Getting the timing right is crucial, as Florida’s unique climate differs greatly from other regions.
Onions are a cool-season crop here, and planting at the correct time ensures they develop strong roots and big bulbs before our heat and humidity arrive. This guide will walk you through the optimal windows for your specific area and the simple steps to follow.
When To Plant Onions In Florida
The best time to plant onions in Florida is during the fall and winter months. For most of the state, the prime planting window runs from October through December. This schedule allows the onions to grow during the cooler, drier part of the year.
They mature in the late winter or early spring, just before the summer rains and intense heat set in. Missing this window often leads to small bulbs or plants that bolt (flower) prematurely.
North, Central, and South Florida Planting Dates
Florida is divided into three main gardening regions, and each has a slightly different ideal schedule. Here’s a quick breakdown:
- North Florida: Plant from October to early December. The cooler winters here are perfect for long-day onion varieties.
- Central Florida: Plant from mid-October through December. This region can sucessfully grow both intermediate-day and some long-day onions.
- South Florida: Plant from November through January. The milder winters mean short-day onion varieties are the best choice here.
Understanding Onion Types: Short-Day vs. Long-Day
Choosing the right type of onion is just as important as the planting date. Onions are categorized by how much daylight they need to form bulbs.
- Short-Day Onions: These begin forming bulbs when they receive 10-12 hours of daylight. They are ideal for South and Central Florida. Popular varieties include ‘Granex’ (the famous Vidalia type), ‘Texas Grano’, and ‘Red Creole’.
- Long-Day Onions: These need 14-16 hours of daylight to bulb and are best for North Florida. Good choices are ‘Sweet Spanish’ and ‘Walla Walla’.
- Intermediate-Day Onions: A flexible option for Central and North Florida, needing 12-14 hours of light. Try ‘Candy’ or ‘Super Star’.
How to Plant Your Onions Step-by-Step
Onions can be planted from seeds, sets (small bulbs), or transplants. For Florida, transplants or sets are often easiest and fastest. Here’s how to get them in the ground.
1. Preparing Your Garden Bed
Onions need loose, well-draining soil and full sun—at least 6-8 hours daily. Raised beds are an excellent option in Florida to improve drainage.
- Work the soil to a depth of about 8 inches, removing any weeds or rocks.
- Mix in 2-3 inches of compost or well-rotted manure. Onions are heavy feeders, so also incorporate a balanced, slow-release fertilizer according to package directions.
- Ensure the bed is level and ready for planting.
2. Planting Transplants or Sets
If using transplants, they often look like small, bare-root plants or come in cell packs. Sets are tiny dormant bulbs.
- Space plants or sets 4-6 inches apart in rows that are 12-18 inches apart.
- Plant them so the base (where the roots start) is just barely covered with soil—no deeper than 1 inch. If using sets, the very tip should peek above the soil.
- Water them in thoroughly after planting to settle the soil around the roots.
3. Starting from Seed
Starting from seed gives you the most variety choices. In Florida, you’ll need to start seeds indoors in late summer (around August or September) to have seedlings ready for the fall planting window.
- Sow seeds in a seed-starting mix about 1/4 inch deep.
- Keep them moist and under a grow light or in a very sunny window.
- Transplant the seedlings outdoors when they are about as thick as a pencil, following the spacing guidelines above.
Caring for Your Growing Onions
Consistent care is key to plump, healthy bulbs. The main tasks are watering, feeding, and weeding.
Watering and Mulching
Onions have shallow roots and need consistent moisture, but they hate soggy feet. Water deeply when the top inch of soil feels dry, usually about 1-2 inches per week.
A layer of straw or pine straw mulch is a game-changer. It conserves moisture, suppresses weeds, and keeps the soil temperature even. Just keep the mulch a little away from the direct base of the plants to prevent rot.
Fertilizing for Success
Feed your onions every 2-3 weeks with a nitrogen-rich fertilizer, like a fish emulsion or a balanced 10-10-10 formula, until the bulbs begin to swell. Once you see the soil start to crack around the forming bulb, switch to a low-nitrogen, high-phosphorus fertilizer to support bulb development.
Weeding and Pest Watch
Keep the area weed-free, as onions don’t compete well. Hand-pull weeds carefully to avoid disturbing the onion’s shallow roots.
Common pests in Florida include thrips, which cause silvery streaks on leaves. A strong spray of water or insecticidal soap can manage them. Good air flow and avoiding overhead watering helps prevent fungal diseases.
Harvesting and Storing Your Florida Onions
Knowing when and how to harvest ensures your onions store well for months.
Signs of Maturity
Onions are ready when the tops (necks) begin to soften, flop over, and turn yellow or brown. This typically happens in late spring. Once about half the tops have fallen over, it’s time to stop watering and prepare for harvest.
The Harvest and Curing Process
- On a dry, sunny day, gently lift the bulbs from the soil with a garden fork.
- Lay them in a single layer right in the garden bed (if no rain is forecast) or in a covered, airy place like a garage or porch.
- Let them cure for 2-3 weeks until the necks are completely dry and papery, and the outer skins are crisp.
After curing, trim the roots and cut the tops down to about an inch. Store your onions in a cool, dry, dark place with good air circulation, like a mesh bag or a wire basket. Properly cured onions from a fall planting can last for many months.
Common Florida Onion Growing Problems
Even with good timing, issues can pop up. Here’s how to troubleshoot:
- Small Bulbs: Usually caused by late planting, using the wrong day-length type for your zone, or insufficient nitrogen early in growth.
- Bolting (Flowering): If an onion sends up a flower stalk, the bulb stops growing. This is often triggered by temperature fluctuations or stress. Use the bulb immediately, as it won’t store well.
- Rotting Bulbs: Caused by overly wet soil or planting too deep. Ensure excelent drainage and proper planting depth.
FAQ: Planting Onions in Florida
Can you plant onions in the spring in Florida?
Generally, no. Spring planting leads to bulbs trying to form as heat and rains arrive, resulting in poor growth and disease. Stick to fall/winter planting.
What are the best onion varieties for Florida?
For South/Central: ‘Granex’, ‘Red Creole’, ‘Texas Grano 1015Y’. For North/Central: ‘Candy’, ‘Yellow Sweet Spanish’, ‘White Sweet Spanish’.
How long do onions take to grow in Florida?
From transplant, most onions take about 90-120 days to reach full maturity. From seed, add 6-8 weeks for the indoor starting period.
Can I grow onions in containers?
Absolutely. Use a pot at least 10 inches deep with drainage holes. Plant 3-4 transplants per large container and water more frequently, as pots dry out faster.
By following this seasonal guide and matching your onion type to your region, you’ll be well on your way to a bountiful harvest of homegrown onions. The sweet, mild flavor of an onion harvested from your own garden is well worth the wait.