Green Onions in Zone 8B — Texas

Green onions are a must-grow for any Texas gardener. Their mild, fresh flavor elevates everything from tacos to salads, and there's nothing quite like snipping a few from your own backyard. Plus, with our long growing season, you can practically have green onions year-round.

Our unpredictable weather and the brutal Texas heat can be tough on some plants, but green onions are surprisingly resilient. With a little planning and attention to watering, you can enjoy a continuous harvest from spring all the way through your fall garden, taking full advantage of our 273-day growing season.

If you're starting green onions from transplants, aim to get them in the ground from late January through late February. This gives them a head start before the Texas heat really kicks in.

Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind. Space them 2-3 inches apart in well-draining soil.

Keep an eye on the forecast, as we can still get unpredictable freezes during this time. Be ready to cover your transplants if a cold snap threatens.

Direct sowing is the easiest way to grow green onions here in Texas, and you can do it from late January through mid September. This gives you plenty of opportunities for successive plantings.

Prepare your soil by loosening it and amending with compost. Green onions prefer soil temperatures between 60-70°F for optimal germination. Sow seeds about ½ inch deep, spacing them 2-3 inches apart. Thin seedlings as needed. You can also plant the root ends of store-bought green onions directly into the soil – a great way to reduce waste and get a quick start!

Green onions need consistent moisture to thrive, especially in the Texas heat. They aren't drought tolerant, and their shallow roots can dry out quickly.

During the spring and fall, aim to water deeply once or twice a week, providing about 1 inch of water each time. In the summer, when temperatures soar, you may need to water every other day or even daily, depending on rainfall and humidity. Use the finger test: if the top 2 inches of soil feel dry, it's time to water.

Water at the base of the plants to avoid wetting the foliage, especially when humidity is high. This helps prevent fungal diseases. Signs of underwatering include wilting and yellowing leaves, while overwatering can lead to root rot. A layer of mulch, like shredded leaves or straw, can help retain moisture and regulate soil temperature.

You can expect your first harvest of green onions about 60-70 days after planting, which means if you plant early, you can harvest from late March through early December.

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 base. If you cut them, they'll often regrow for a second harvest.

To extend your harvest, plant successive crops every few weeks. As the first frost approaches in late November, harvest any remaining green onions or cover them with a thick layer of mulch to protect them from the cold. They may survive a light frost and continue to produce.

Here are some common problems you might encounter growing green onions in Texas:

• Onion Maggots
• What it looks like: Wilting or yellowing plants, stunted growth, and small white maggots feeding on the roots and bulb.
• What causes it: These pests thrive in moist soil and can be a problem, especially after periods of heavy rainfall or flash floods.
• How to fix/prevent it: Use row covers to prevent egg-laying. Remove and destroy infested plants. Till the soil before planting to disrupt the maggot life cycle.
• Thrips
• What it looks like: Silver streaks or stippling on leaves, distorted growth, and tiny, slender insects on the plant.
• What causes it: Thrips are attracted to stressed plants and can be more of a problem during hot, dry periods.
• How to fix/prevent it: Provide adequate water and fertilizer to keep plants healthy. Use insecticidal soap or neem oil to control infestations.
• 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.
• Pink Root
• What it looks like: Pink or reddish roots, 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 to avoid planting onions in the same spot year after year. Plant resistant varieties if available.

Texas Specific Challenges: The hot-to-extreme heat and variable humidity can create a breeding ground for pests and diseases. Monitor your plants regularly and take action quickly to prevent problems from spreading. Fire ants can also be a nuisance, so keep your garden free of debris and use appropriate bait if necessary.

Green onions are great companions for many plants in your Texas garden:

• Carrots: Green onions repel carrot root flies, protecting your carrot crop.
• Lettuce: Green onions help deter aphids, which can plague lettuce.
• Tomatoes and Peppers: Green onions can repel some pests that attack tomatoes and peppers, like spider mites.
• Beets: Green onions can help deter flea beetles from beets.

Avoid planting green onions near beans or peas, as they can inhibit each other's growth.