Green Onions in Zone 6B — Texas

Green onions are a fantastic addition to any Texas garden. Their mild, fresh flavor elevates everything from tacos to salads, and they're incredibly versatile in the kitchen. Plus, you can snip off what you need as you need it, right from your backyard. There's nothing quite like the taste of freshly harvested green onions, especially after enduring the Texas heat!

While our unpredictable weather and occasional extreme heat can be a challenge, green onions are surprisingly resilient. With a little planning and attention, you can enjoy a continuous harvest throughout our long 230-day growing season. Timing is key, and you'll find that planting in succession makes all the difference.

If you're starting your green onions indoors or buying transplants, get them in the ground sometime between late February through late March. Remember to harden them off by gradually exposing them to the outdoors for about a week before planting. This prevents transplant shock.

Plant your green onion transplants about 2-3 inches apart in rows. The spacing helps with air circulation.

Keep an eye on the weather. Late freezes can happen, so be prepared to cover your young plants if temperatures dip unexpectedly.

Direct sowing is the easiest way to grow green onions in Texas. Plant seeds from late February through late August for a continuous supply. You can even plant the root ends of store-bought green onions.

Choose a spot with full sun to partial shade and prepare the soil by loosening it and adding compost. Green onions prefer well-drained soil. Sow seeds about ½ inch deep and 2-3 inches apart. Keep the soil consistently moist until the seedlings emerge. Soil temperatures should ideally be above 50°F for good germination.

Don't overcrowd them! Proper spacing will help prevent disease and allow for better growth.

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

During the spring and fall, when temperatures are milder, aim to water deeply once or twice a week, providing about 1 inch of water each time. In the heat of summer, you may need to water every other day, or even daily, to keep the soil consistently moist. Use the "finger test" – stick your finger about 2 inches 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, especially with our variable humidity. However, with the dry heat, overhead watering in the mornings can help keep plants cool.

Signs of underwatering include wilting and yellowing leaves. Overwatering can lead to root rot, indicated by soggy soil and stunted growth. A light layer of organic mulch, like shredded leaves or straw, can help retain moisture and regulate soil temperature, which is crucial during those hot Texas summers.

You can expect your first harvest of green onions from late April through mid November, about 60 days after planting. Look for stalks that are at least pencil-thick.

To harvest, you can either pull the entire plant or cut the green onion about an inch above the soil line. If you cut them, they'll often regrow, giving you multiple harvests from a single planting. Snip off the green tops as needed.

To keep the harvest going, make successive sowings every few weeks. As the first frost approaches around early November, harvest any remaining green onions. You can also pot some up and bring them indoors to extend the harvest through the winter.

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

Onion Maggots

• What it looks like: Wilting or yellowing leaves, stunted growth, and small white maggots feeding on the roots and bulb.
• What causes it: These pests are attracted to the smell of onions and thrive in moist soil.
• How to fix/prevent it: Use row covers to prevent the adult flies from laying eggs. Apply beneficial nematodes to the soil. Remove and destroy any infested plants.

Thrips

• What it looks like: Silvery or distorted leaves with tiny black specks (thrip droppings).
• What causes it: These tiny insects suck plant juices, causing damage. They are more prevalent during hot, dry weather.
• How to fix/prevent it: Encourage beneficial insects like ladybugs and lacewings. Spray plants with insecticidal soap or neem oil, paying attention to undersides of leaves.

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, moist conditions.
• How to fix/prevent it: Improve soil drainage. Rotate crops. Plant resistant varieties if available. Solarize the soil during the hottest part of the summer to kill the fungus.

Texas Specific Challenges: The combination of hot-to-extreme heat, variable humidity, and unpredictable rainfall in Texas can create ideal conditions for pests and diseases. Monitor your plants closely and take action quickly to prevent problems from escalating. Fire ants can also be a nuisance, disturbing the soil around your green onions. Use appropriate bait to control them.

Companion planting can really help your green onions thrive in Texas. Carrots are great companions because they deter onion flies, while green onions deter carrot root flies. Lettuce provides ground cover, keeping the soil cool and moist, which is especially helpful during our hot summers.

Tomatoes and peppers benefit from being planted near green onions because the onions repel aphids and other pests. Beets also make good companions, as they don't compete for the same nutrients and can help improve soil structure.

Avoid planting beans and peas near green onions, as they can inhibit each other's growth. Beans and peas are nitrogen fixers, while onions require sulfur.