How To Grow Onions In Florida

If you want to grow onions in Florida, you’re in the right place. Our unique climate offers a long, productive season for these essential veggies, but it requires a specific approach. This guide gives you the practical steps and Florida gardening tips for a successful harvest right in your backyard.

Onions are a rewarding crop. They don’t need a ton of space and can be grown alongside many other garden favorites. The key in Florida is understanding our seasons and choosing the right varieties. Let’s get started.

Success with onions here hinges on three things: timing, type, and technique. Forget what works up north; Florida’s warm winters and hot summers dictate a different calendar.

Understanding Florida’s Onion Seasons

In most of Florida, onions are a cool-season crop. We grow them through the fall and winter for a spring harvest. This avoids our brutal summer heat, which can cause bulbs to stop forming or bolt to seed.

North Florida: Plant sets or transplants from October through December.
Central Florida: The prime planting window is from November through January.
South Florida: You can plant from December through February, sometimes even into early March.

The general rule is to get them in the ground so they can develop roots and leaves during cooler weather. Bulb formation happens as days get longer in late winter and spring.

Choosing the Right Onion Varieties

This is the most critical step. Onions are classified by day-length: short-day, intermediate-day, and long-day. Florida gardeners must almost exclusively use short-day varieties.

Short-Day Onions: These form bulbs when daylength reaches 10-12 hours. Perfect for our southern latitudes. Excellent choices include ‘Texas Grano’, ‘Granex’ (the famous Vidalia type), ‘Red Burgundy’, and ‘White Bermuda’.
Intermediate-Day Onions: Can work in North Florida if planted early. Try ‘Candy’ or ‘Super Star’.
Avoid Long-Day Varieties: These need 14+ hours of daylight to bulb, which we don’t get. Planting common northern varieties like ‘Walla Walla’ will result in no bulb formation.

Planting Methods: Seeds, Sets, or Transplants?

You have three options, each with pros and cons.

Seeds: Most economical. Start indoors in late summer (Sept-Oct) for fall transplanting. Gives you the widest variety choice.
Sets (Small Bulbs): Easiest and fastest. Plant them directly in the garden pointy-side up. However, variety selection is limited, and they are more prone to bolting.
Transplants (Seedlings): The most reliable method for many. You can buy bundles or start your own. They establish quickly and are less likely to bolt than sets.

Step-by-Step Planting Guide

Site Selection: Pick a spot with full sun—at least 6-8 hours daily. Onions won’t bulb well in shade.
Soil Preparation: Florida’s sandy soil needs help. Work in 3-4 inches of compost or well-rotted manure. Aim for a loose, well-draining soil with a pH between 6.0 and 6.8. A soil test is always a good idea.
Planting: Space plants or sets 4 inches apart in rows 12-18 inches apart. If growing for green onions, you can plant closer. Plant transplants about 1 inch deep, and sets just deep enough to cover the bulb.
Watering: Water immediately after planting. Provide 1 inch of water per week, keeping the soil consistently moist but not soggy. Drip irrigation is ideal to keep foliage dry and prevent disease.

Care and Maintenance Through the Season

Consistent care is simple but vital for good bulb development.

Fertilizing: Use a balanced fertilizer (like 10-10-10) at planting. Side-dress with a nitrogen-rich fertilizer every 3-4 weeks until bulbs begin to swell. Stop fertilizing once bulbing starts.
Weeding: Onions have shallow roots. Hand-pull weeds carefully to avoid damaging the bulbs. A layer of straw mulch can supress weeds and retain moisture.
Pest & Disease Watch: Thrips are the main pest, causing silvery streaks on leaves. Treat with insecticidal soap. For diseases like downy mildew, ensure good air circulation and avoid overhead watering. Crop rotation is essential.

The Harvest and Curing Process

Knowing when and how to harvest ensures your onions store well.

Signs of Maturity: Tops will begin to yellow, flop over, and neck (the area just above the bulb) will soften. This usually happens in late March through May.
Harvesting: Gently lift bulbs with a garden fork on a sunny, dry day. Handle them carefully to avoid bruising.
Curing: This step is non-negotiable for storage onions. Lay bulbs in a single layer in a warm, dry, airy place out of direct sun (like a garage or covered porch) for 2-3 weeks. The outer skins will become papery and the necks will dry completely.
Storage: After curing, trim roots and cut tops back to 1 inch. Store in a cool, dry, dark place in mesh bags or a single layer. Properly cured short-day onions can last several months.

Common Florida Onion Growing Problems

No Bulb Formation: Caused by planting the wrong day-length type or planting too late.
Bolting (Flowering): Triggered by temperature fluctuations or stress. Use transplants over sets, and choose bolt-resistant varieties.
Small Bulbs: Often due to overcrowding, insufficient nitrogen early on, or competition from weeds.
Rot in Ground: Usually a sign of poorly draining soil or to much rainfall during the curing process in the field.

Florida Gardening Tips for Success

Here are some extra insights tailored to our state.

In South Florida, you can sucesfully grow green onions year-round. Just snip what you need.
Consider raised beds if your native soil is very poorly draining or compacted.
Keep a garden journal. Note planting dates and varieties that perform best in your micro-climate.
Don’t be afraid to ask at your local county Extension office. They have specific, free advice for your area.

FAQ: Florida Onion Gardening

Can you grow onions year-round in Florida?

You can grow green onions year-round in most parts of the state. But for large storage bulbs, the fall/winter planting schedule is essential.

What are the best onions to grow in Florida?

Stick with proven short-day varieties like ‘Granex’, ‘Texas Grano’, ‘Red Burgundy’, and ‘Southern Belle Red’.

How often should you water onions in Florida?

Water deeply once or twice a week to provide about 1 inch of water, adjusting for rainfall. Sandy soil dries out fast, so check moisture frequently.

Why are my onion tops falling over?

If it’s near harvest time, this is normal maturity. If it happens early in the season, it could be overwatering, disease, or pest damage like thrips.

Growing onions in Florida is a satisfying project that pays off with sweet, homegrown flavor. By following these Florida gardening tips for timing and selection, you’ll be harvesting basketfuls of beautiful bulbs by spring. Remember, start with short-day varieties, plant in the cool season, and give them the simple care they need. Your kitchen will thank you.