Green Onions in Zone 8A — Florida

Green onions are a must-grow in any Florida garden. They add a fresh, mild bite to your cooking, and their versatility is unmatched. Plus, nothing beats the satisfaction of snipping off exactly what you need right before dinner, especially when you can do it almost year-round here!

Our Florida gardening calendar is different, with summer being more of a survival mode than a peak season. But don’t let that scare you! Green onions are relatively easy to grow, and with our long 283-day growing season, you'll have plenty of opportunities for success.

You can transplant green onion seedlings outdoors in late January through late February. Before planting, make sure you harden off your seedlings. This means gradually exposing them to outdoor conditions for about a week.

Space your transplants 2-3 inches apart in well-draining soil. Keep an eye on the weather, as we can still get some unexpected cold snaps this time of year. A little frost cloth can go a long way to protect those tender seedlings.

Direct sowing is the easiest way to grow green onions in Florida. Sow seeds late January through late September for a continuous harvest. Green onions are pretty forgiving, so don't stress too much about the timing.

Choose a spot with full sun to partial shade and prepare the soil by loosening it and adding some compost. Sow seeds about ¼ inch deep, spacing them 2-3 inches apart. Keep the soil consistently moist until germination. Also, don't forget you can plant the root ends of store-bought green onions for a quick and easy start!

Green onions need consistent moisture to thrive, but in Florida, it's a balancing act. Our summers are hot and humid, and fungal diseases love that combination. You need to water smart.

During the drier spring and fall months, aim for about 1 inch of water per week, either from rain or irrigation. Do the finger test: stick your finger about 2 inches deep into the soil. If it feels dry, it's time to water. In our wet summer months, you might not need to water at all, unless we're in a dry spell. When you do water, do it at the base of the plants to avoid wetting the foliage and encouraging fungal growth.

Overwatering can lead to rot, while underwatering results in tough, strong-tasting onions. Yellowing leaves can be a sign of either, so pay attention. A light layer of mulch, like pine straw, can help retain moisture and suppress weeds, but avoid piling it up against the stems.

You can expect your first harvest of green onions about 60 days after planting, so from late March through mid December depending on when you sowed. They're ready to harvest when the stalks are about pencil-thick. Don't wait too long, or they can get too strong.

You can either pull the entire plant or snip off the green tops about an inch above the soil. If you cut them, they'll usually regrow, giving you multiple harvests. As the first frost approaches around early December, harvest any remaining green onions to use fresh or preserve.

Green onions are generally easy to grow, but here are some common problems to watch out for in Florida:

Onion Maggots

• What it looks like: Wilting plants, yellowing leaves, and small white maggots feeding on the roots and bulb.
• What causes it: These pests thrive in moist soil.
• How to fix/prevent it: Use row covers to prevent adult flies from laying eggs. Introduce beneficial nematodes to the soil.

Thrips

• What it looks like: Silvery streaks on leaves, distorted growth, and tiny, slender insects visible on the plant.
• What causes it: Thrips are attracted to stressed plants and dry conditions.
• How to fix/prevent it: Keep plants well-watered. Spray with insecticidal soap or neem oil. Encourage beneficial insects like ladybugs.

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. Different species affect different plants.
• 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: Roots turn pink or reddish, stunted growth, and yellowing leaves.
• What causes it: A soilborne fungus that thrives in warm, wet conditions.
• How to fix/prevent it: Improve soil drainage. Rotate crops. Use nematode-resistant varieties. Solarize the soil during the hot summer months.

Florida Specific Challenges: Our hot, humid summers and sandy soil create a perfect environment for fungal diseases and nematodes. Choose nematode-resistant varieties, improve soil drainage with plenty of compost, and be diligent about watering at the base of the plants to minimize these problems.

Green onions are great companions for many plants in your Florida garden. Carrots benefit because the onion scent deters carrot root flies. Lettuce thrives nearby, as green onions repel aphids that might otherwise bother the lettuce. Tomatoes and peppers also appreciate green onions, as they can deter various pests. Beets grow well with green onions too, as they can help deter leaf miners.

However, avoid planting green onions near beans and peas. They can inhibit the growth of these legumes. Keeping these companions in mind will help you maximize your yields and minimize pest problems in your Florida garden.