Green Onions in Zone 8A — Southeast

Green onions are a must-grow here in the Southeast. They add a fresh, mild bite to everything from summer salads to grilled fish, and they're so easy to snip as needed. Plus, you can't beat the satisfaction of pulling your own onions from the garden instead of buying them at the store.

Our long summer and reliable rainfall mean green onions can thrive here with a little attention. We do have our challenges with humidity and pests, but with smart timing and a few simple practices, you can have a steady supply of these tasty alliums from spring well into fall, thanks to our 245-day growing season.

You can transplant green onion seedlings outdoors from mid-February through mid-March. This gives them a head start before the real heat kicks in. Be sure to harden off your seedlings for about a week before planting. Gradually expose them to outdoor conditions to prevent shock.

Space the seedlings about 2-3 inches apart in well-draining soil. Keep an eye on the weather forecast – those late cold snaps we sometimes get in early spring can set them back, so be ready to cover them if needed.

Direct sowing is the easiest way to grow green onions here in the Southeast. Sow seeds from mid-February through early September for a continuous harvest. Green onions aren't too picky about soil, but they'll do best in loose, well-draining soil amended with compost.

Plant the seeds about ¼ inch deep and 2-3 inches apart. Keep the soil consistently moist until they germinate, which usually takes about a week or two, depending on soil temperature. A trick some of us use is to plant the root ends of store-bought green onions. Just stick them in the ground, and they'll regrow!

Green onions need consistent moisture to stay tender and mild, especially with our long, hot summers. They aren't drought-tolerant, and their shallow roots can dry out quickly. You've got to stay on top of watering, especially during those dry spells between our afternoon thunderstorms.

During the spring and fall, when temperatures are milder, aim for about 1 inch of water per week. In the heat of summer, you might need to increase that to 1.5-2 inches, especially if it hasn't rained. Stick your finger about 2 inches deep into the soil – if it feels dry, it's time to water. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our humid climate.

Yellowing leaves can be a sign of underwatering, while mushy or rotting stalks can indicate overwatering. A light layer of mulch, like pine straw, can help retain moisture and keep the soil cooler during the summer months.

You can expect your first harvest of green onions about 60 days after planting, so from mid-April through late November. They're ready to harvest when the stalks are about pencil-thick. You can either pull up the entire plant or cut the stalks about an inch above the soil line. Cutting them encourages regrowth, giving you a continuous harvest.

For continuous production, harvest only what you need and leave the rest to keep growing. As our first frost approaches in mid-November, harvest any remaining green onions. You can chop and freeze them for later use in soups, stews, and other dishes.

Here are some common problems you might encounter with green onions in the Southeast:

• Onion Maggots
• What it looks like: Wilting or yellowing leaves, stunted growth, and small white maggots feeding on the roots.
• What causes it: These pests are attracted to the smell of onions and lay their eggs near the base of the plants.
• How to fix/prevent it: Use row covers to prevent the adult flies from laying eggs. Introduce beneficial nematodes to the soil.
• Thrips
• What it looks like: Silver streaks or spots on the leaves, distorted growth, and tiny, slender insects on the plants.
• What causes it: Thrips thrive in hot, dry conditions and suck the sap from the leaves.
• How to fix/prevent it: Encourage beneficial insects like ladybugs and lacewings. Use insecticidal soap or neem oil, especially after a dry spell.
• 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: Roots turn pink or reddish, and the plants become stunted and may wilt.
• What causes it: A soilborne fungus that thrives in warm, wet conditions.
• How to fix/prevent it: Improve soil drainage. Rotate crops to avoid planting onions in the same spot year after year. Solarize the soil during the hot summer months to kill the fungus.

Southeast Specific Challenges: Our hot, humid summers and frequent rainfall create ideal conditions for fungal diseases like downy mildew and pink root. Good air circulation, proper watering techniques (at the base of the plant), and crop rotation are essential for keeping your green onions healthy.

Good companions for green onions include carrots, lettuce, tomatoes, peppers, and beets. Carrots help deter onion flies, while green onions repel aphids and other pests that can bother tomatoes and peppers. Lettuce benefits from the shade provided by green onions, keeping the soil cooler during our hot summers. Beets and green onions don't compete for nutrients, making them a great combination. Avoid planting green onions near beans and peas, as they can inhibit each other's growth.