Green Onions in Zone 10A — Florida

Green onions are a must-grow in any Florida garden. Their mild, fresh flavor elevates everything from tacos to salads, and the satisfaction of snipping them fresh from your backyard is unmatched. Plus, they're one of the easiest crops to keep going nearly year-round here, and they thrive even in our partial shade spots.

Sure, Florida gardening has its challenges, like humidity and nematodes, but green onions are surprisingly resilient when you time things right. With our extended growing season – around 355 days – you can practically always have a patch of green onions ready to harvest.

Transplanting green onions is a great way to get a head start, especially if you're aiming for an early harvest. Aim to get those transplants in the ground from mid-December through early January. This timing lets them establish before our brief cool snap truly hits.

Before planting, be sure to harden off your seedlings. Give them about a week of gradually increasing outdoor exposure to acclimate to the Florida sunshine and humidity. Space the transplants 2-3 inches apart, giving them room to grow without overcrowding. Keep an eye on the weather forecast; an unexpected cold front can stress young transplants, so be ready to cover them if needed.

Direct sowing is the easiest and most common method for growing green onions here in Florida. You can sow seeds from mid-December all the way through mid-October, giving you multiple chances for a continuous harvest. Green onions are pretty forgiving.

Before sowing, loosen the soil and amend it with compost to improve drainage and fertility. Green onions prefer well-draining soil, which is especially important with our high humidity. Sow seeds about ¼ inch deep and 2-3 inches apart. Keep the soil consistently moist until germination, which usually takes about a week or two. A fun trick: you can also plant the root ends of store-bought green onions; just stick them in the soil and watch them regrow!

Green onions need consistent moisture to thrive, but overwatering in Florida's humid climate can lead to problems. They aren't very drought-tolerant, so you'll need to stay on top of it, especially during our drier periods.

During the cooler months (late fall through early spring), when rainfall is less frequent, aim to water your green onions about 1 inch per week. In the hotter, wetter summer months, you might not need to water at all, thanks to our frequent afternoon showers. Stick your finger about 2 inches into the soil; if it feels dry, it's time to water. Always 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 or yellowing leaves. Overwatering can lead to yellowing, stunted growth, and potentially root rot. A light layer of mulch, like pine straw, can help retain moisture in the soil and suppress weeds, which is always a plus in Florida.

You can start harvesting your green onions as early as mid-February through early January, usually about 60 days after planting. The best time to harvest is when the stalks are about pencil-thick.

To harvest, you can either pull up the entire plant or snip the green stalks about an inch above the soil line. If you cut them, the green onions will often regrow, giving you multiple harvests from a single planting. To encourage continued production, be sure to fertilize lightly after harvesting. As late December approaches, and our first frost is on the horizon, harvest any remaining green onions to use fresh or freeze for later.

Green onions, like any crop, can face some challenges in Florida. Here are some common problems and how to deal with them:

• Onion Maggots
• What it looks like: Plants wilt and die, and you'll find small, white maggots feeding on the roots and bulb.
• What causes it: These pests thrive in moist soil and can quickly decimate a crop.
• How to fix/prevent it: Use row covers to prevent the adult flies from laying eggs. Rotate your crops to avoid building up populations in the soil.
• Thrips
• What it looks like: Silvery streaks or spots on the leaves, distorted growth, and tiny, slender insects.
• What causes it: Thrips are attracted to dry conditions and can become a problem during our drier spring months.
• How to fix/prevent it: Encourage beneficial insects like ladybugs and lacewings. Insecticidal soap can also be effective.
• 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: An 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.
• Pink Root
• What it looks like: Roots turn pink or reddish, and plants become stunted and weak.
• What causes it: A soilborne fungus that thrives in warm, moist conditions.
• How to fix/prevent it: Improve soil drainage and avoid overwatering. Rotate crops and consider solarizing the soil to kill the fungus.

Florida Specific Challenges: Our hot, humid summers and wet-summer rainfall create the perfect environment for fungal diseases. Nematodes in our sandy soil can also be a problem, so amend your soil with plenty of organic matter and consider using nematode-resistant varieties if you have a severe infestation.

Companion planting can help your green onions thrive in your Florida garden. Carrots are great companions because their scent repels onion flies. Lettuce benefits from the shade provided by green onions, which helps prevent bolting in the Florida heat. Tomatoes and peppers also benefit from being planted near green onions, as they deter certain pests. Beets are also good companions.

Avoid planting green onions near beans and peas. These legumes can inhibit the growth of onions.