Green Onions in Zone 6B — Southeast

Green onions are a must-grow here in the Southeast. Their fresh, mild flavor elevates everything from summer salads to grilled dishes, and they're incredibly versatile in Southern cooking. Plus, there’s nothing quite like the satisfaction of snipping a few green onions from your own garden for supper on a warm evening.

Our long growing season makes it easy to keep green onions going for months. Sure, we have to deal with humidity and the occasional pest, but with a little attention to timing, you can enjoy fresh green onions from early May all the way through late fall. That’s a solid return for a plant that thrives in our 208-day season.

You can transplant green onion seedlings outdoors in early March through early April. Before you put them in the ground, you'll want to harden them off. Give them about a week of gradually increasing exposure to the outdoors so they can adjust to the sun and wind.

Space your transplants about 2-3 inches apart in well-drained soil. Keep an eye on the weather, as late cold snaps can still happen in early spring. If a frost is predicted, cover your young plants with a frost blanket or cloche.

Direct sowing is definitely the way to go with green onions here. You can start sowing seeds as early as early March and continue through mid-August for a continuous supply. Make sure the soil temperature is at least 50°F for good germination.

Work some compost into your clay soil to improve drainage and fertility, then sow seeds about ½ inch deep, spacing them 2-3 inches apart. You can also plant the root ends of store-bought green onions – just stick the white part with the roots into the soil, and they'll regrow. Keep the soil consistently moist, and you'll see sprouts in no time.

Green onions need consistent moisture to thrive, especially during our hot, humid summers. They aren't drought tolerant, and their shallow roots can dry out quickly. A good rule of thumb is to give them about 1 inch of water per week, either from rainfall or irrigation.

The finger test is your friend: stick your finger about 2 inches into the soil near the plants. 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. Overhead watering is risky in the Southeast.

Signs of underwatering include yellowing leaves and stunted growth. Overwatering, on the other hand, can lead to root rot, which shows as wilting or mushy stems. A layer of mulch around the base of your plants will help retain moisture and suppress weeds – pine straw works great in our acidic soils.

Here in Zone 6B, Southeast, you can expect your first harvest of green onions starting in early May and continuing through early November. They're usually ready to harvest about 60 days after planting, when the stalks are about pencil-thick. Don't worry if they're not perfect; they're still delicious even when a bit smaller.

You can either pull up the entire plant or cut the stalks off above the base, leaving the roots in the ground for regrowth. Cutting them encourages continuous production. If you want to keep them producing as long as possible, be sure to snip off any flower stalks that appear.

As we approach late October and the first frost, harvest any remaining green onions or cover them with a thick layer of mulch for a bit of extra protection. You might be surprised how long they'll keep producing with a little help.

Green onions are generally easy to grow, but here are a few common problems we face in the Southeast:

• 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 are attracted to the smell of onions and lay their eggs at 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 to attack the larvae.
• Thrips
• What it looks like: Silvery streaks 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. Spray plants with a strong stream of water to dislodge thrips. 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: This oomycete pathogen 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: Pink or reddish roots, stunted growth, and yellowing leaves.
• What causes it: This soilborne fungus thrives in warm, wet conditions and infects the roots.
• How to fix/prevent it: Improve soil drainage by adding organic matter. Practice crop rotation. Solarize the soil during the hot summer months to kill the fungus.

Southeast Specific Challenges: Our hot, humid summers create the perfect environment for fungal diseases like downy mildew and pink root. Maintaining good air circulation and avoiding overhead watering are key to keeping your green onions healthy. Also, keep an eye out for Japanese beetles, which can sometimes munch on the leaves, though they usually prefer other plants.

Companion planting can really help your green onions thrive. Carrots make great companions because their scent repels onion flies. Lettuce also works well, as it provides ground cover and helps keep the soil cool and moist.

Tomatoes and peppers benefit from being planted near green onions, as the onions can deter certain pests. Beets are another good choice, as they don't compete for the same nutrients in the soil. On the other hand, avoid planting green onions near beans or peas, as they can inhibit each other's growth.