Green Onions in Zone 9A — Texas

Green onions are a must-grow here in Texas. Their mild, fresh flavor elevates everything from tacos to salads, and they're incredibly versatile in the kitchen. Plus, there's nothing quite like the satisfaction of snipping a few from your own garden for a quick dinner.

We all know the Texas weather can be unpredictable, and extreme heat is a real concern for many garden plants. But with a long growing season of nearly 300 days, you can easily time your green onion planting for success. You'll have plenty of chances to get it right, even with our variable conditions.

You can transplant green onion seedlings outdoors in Texas from mid-January through mid-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.

Space the transplants 2-3 inches apart in well-draining soil. Keep an eye on the weather forecast – a late freeze is always possible, so be ready to cover your young plants if needed. Water them in well after transplanting.

Direct sowing is the easiest way to grow green onions in Texas. You can sow seeds directly into your garden beds from mid-January through late September, giving you multiple planting windows. Soil temperatures between 50°F and 80°F are ideal for germination.

Prepare your soil by loosening it and adding compost. Sow seeds about ¼ inch deep and 2-3 inches apart. Keep the soil consistently moist until the seedlings emerge, usually within a week or two. For an even simpler approach, plant the root ends of store-bought green onions; just stick them in the ground and keep them watered.

Green onions need consistent moisture to thrive, but they don't like soggy soil. In our Texas climate, that can be a tricky balance. During the hotter months, you'll likely need to water deeply every few days, especially if rainfall is scarce, which is often the case. In the cooler months, you can usually reduce watering to once a week, depending on rainfall.

Stick your finger about 2 inches into the soil near your green onions. If it feels dry, it's time to water. Aim for about 1 inch of water per week, either from rainfall or irrigation. Water at the base of the plants to avoid wetting the foliage, which can encourage disease in our variable humidity.

Yellowing leaves can indicate underwatering, while stunted growth and yellowing can signal overwatering. A layer of mulch, like shredded leaves or pine straw, can help retain moisture in the soil and regulate soil temperature, which is especially helpful during the Texas heat.

You can expect your first harvest of green onions about 60 days after planting, starting in mid-March and continuing through mid-December. Look for stalks that are at least pencil-thick. The green tops should be firm and vibrant.

To harvest, you can either pull up the entire plant or snip off the green tops about an inch above the soil line. If you cut them, the plants will regrow, giving you multiple harvests. As our first frost approaches in early December, harvest any remaining green onions and store them in the refrigerator or freezer.

Here are some common problems you might encounter with 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 during wetter periods in the spring or fall.
• How to fix/prevent it: Use row covers to prevent the adult flies from laying eggs near your plants. Introduce beneficial nematodes to the soil. Rotate your crops each year.
• Thrips
• What it looks like: Silvery streaks or white patches on the leaves, distorted growth, and tiny, slender insects crawling on the plants.
• What causes it: Thrips are attracted to dry conditions and can become a problem during our hot, dry summers.
• How to fix/prevent it: Increase humidity by watering regularly. Spray plants with insecticidal soap or neem oil. Encourage beneficial insects like ladybugs and lacewings.
• 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 discoloration of the 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 by adding organic matter. Rotate your crops. Plant resistant varieties if available. Solarize the soil during the hottest part of the summer to kill the fungus.

Texas Specific Challenges: The unpredictable rainfall and variable humidity in Texas can make it challenging to manage diseases like downy mildew. Our extreme heat during the summer can also stress plants, making them more susceptible to pests. Consistent monitoring and proactive measures are key to keeping your green onions healthy. And watch out for those fire ants when you're working in the garden!

Green onions make great neighbors in the garden. Plant them near carrots to deter carrot root flies, and the onions will benefit from the carrots' soil-loosening action. Lettuce thrives in the partial shade provided by green onions, and green onions can help repel aphids from tomatoes and peppers. Beets also benefit from the pest-repelling properties of green onions.

Avoid planting green onions near beans or peas. These legumes can inhibit onion growth, and the onions can interfere with the nitrogen-fixing abilities of the legumes. Keep them separated for best results in your Texas garden.