Green Onions in Zone 9B — Florida

Green onions are a must-grow in any Florida garden. Their mild, fresh flavor elevates everything from tacos to salads, and they’re incredibly versatile in the kitchen. Plus, the satisfaction of snipping fresh green onions from your own backyard, especially during our cooler months, is hard to beat!

Sure, Florida gardening has its challenges – humidity, nematodes, and the occasional hurricane, but with a little planning, you can enjoy a continuous harvest of green onions. Our long, 344-day growing season means you can plant them almost year-round, making them a reliable staple in your garden.

If you're starting your green onions from transplants, aim to get them in the ground between late December and mid January. This gives them a good start before our weather starts to warm up significantly.

Before transplanting, harden them off by gradually exposing them to the outdoor elements for about a week. This helps them adjust to the Florida sunshine and humidity.

When transplanting, space them about 2-3 inches apart in well-draining soil. Keep an eye on the weather forecast – those occasional cool snaps can still happen, so be prepared to cover them if a frost threatens.

Direct sowing is the easiest way to grow green onions here in Florida. You can sow seeds directly into the garden from late December all the way through mid October. That's a long window!

Prepare your soil by loosening it and amending with compost. Green onions aren't too picky, but well-draining soil is a must to prevent rot. Sow seeds about ¼ inch deep and 2-3 inches apart. Keep the soil consistently moist until germination. For a continuous supply, sow a new batch every few weeks. You can even plant the root ends of store-bought green onions – just stick them in the soil, and they'll regrow!

Green onions need consistent moisture to thrive, but like many plants here, they don't like soggy soil. In our Florida climate, that balance can be tricky, especially with our high humidity.

During the cooler, drier months (fall through spring), you'll likely need to water your green onions about 1 inch per week, especially if we're not getting much rain. Use the finger test – stick your finger about 2 inches into the soil; if it feels dry, it's time to water. In the summer, with our frequent rainfall, you might not need to water at all unless we're experiencing a dry spell.

Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our humid environment. Signs of underwatering include wilting and yellowing leaves, while overwatering can lead to yellowing leaves and root rot. Adding a layer of mulch, like pine straw or wood chips, can help retain moisture and suppress weeds, but be careful not to pile it up against the stems.

You can expect your first harvest of green onions from late February through early January, about 60 days after planting. They're usually ready when the stalks are about pencil-thick.

To harvest, you can either pull the entire plant or, for a continuous harvest, cut the green onion about an inch above the soil line. The plant will then regrow, giving you multiple harvests.

As late December approaches and our first frost becomes a possibility, harvest any remaining green onions that are close to maturity. While they can tolerate a light frost, a hard freeze can damage them.

Green onions, like many crops in Florida, can face a few pest and disease challenges. Here's what to watch out for:

• Onion Maggots
• What it looks like: Wilting plants, yellowing leaves, and small white maggots feeding on the roots and bulb.
• What causes it: These maggots are the larvae of a fly that lays its eggs near the base of onion plants. They thrive in moist soil.
• How to fix/prevent it: Use row covers to prevent the flies from laying eggs. Introduce beneficial nematodes to the soil. Rotate your crops to avoid planting onions in the same spot year after year.
• Thrips
• What it looks like: Silver streaks or white blotches on the leaves. The leaves may also become distorted or curl. You might see tiny, slender insects on the plants.
• What causes it: Thrips are tiny insects that suck the sap from plants. They're more prevalent during hot, dry weather.
• How to fix/prevent it: Encourage beneficial insects like ladybugs and lacewings. Use insecticidal soap or neem oil, making sure to spray both sides of the leaves. Water plants regularly to reduce stress.
• Downy Mildew
• What it looks like: Yellow patches on leaf tops with fuzzy gray-purple growth on undersides. Leaves brown and die from the bottom up.
• What causes it: Oomycete pathogen that spreads in cool, humid conditions via wind-carried spores.
• How to fix/prevent it: Remove affected leaves immediately. Improve air circulation. Water at the base, never overhead. Copper-based fungicides for prevention. Plant resistant varieties where available.
• Pink Root
• What it looks like: The roots turn pink or reddish, and the plant's growth is stunted.
• What causes it: A soilborne fungus that thrives in warm, moist soil.
• How to fix/prevent it: Improve soil drainage. Rotate your crops. Solarize the soil during the summer to kill the fungus.

Florida Specific Challenges: Our hot, humid summers and sandy soil can exacerbate these problems. The high humidity promotes fungal diseases like downy mildew, while the sandy soil can make plants more susceptible to nematodes. Be vigilant about monitoring your plants and taking action at the first sign of trouble.

Green onions make great companions for many plants in your Florida garden! Carrots benefit from the onion's pungent smell, which deters carrot root flies. Lettuce thrives in the partial shade provided by green onions, especially during our warmer months. Tomatoes and peppers also benefit because the onions deter pests like aphids. Beets are another good companion, as green onions can help repel leaf miners that can damage beet foliage.

Avoid planting green onions near beans and peas. Onions can inhibit the growth of these legumes. Keeping these companions in mind can help you create a thriving and pest-resistant garden.