How to Grow Green Onions: 3 Methods for Success

You can grow fresh green onions in just 7-10 days using kitchen scraps, with no garden required. This complete guide reveals three proven methods (soil, water, and regrowth), optimal conditions, and harvesting tips for continuous supply of crisp, flavorful scallions year-round.

Nothing beats the taste of homegrown green onions—crisp, vibrant, and packed with fresh flavor. Whether you're a beginner gardener with limited space or an experienced grower looking for quick results, this guide delivers everything you need to successfully cultivate green onions (Allium fistulosum) indoors or outdoors. Forget expensive store-bought bundles that wilt within days; with these simple techniques, you'll enjoy a continuous harvest of fresh scallions for salads, stir-fries, and garnishes.

Why Green Onions Are Perfect for Home Growing

Green onions rank among the easiest vegetables to grow, making them ideal for beginners. Unlike many crops, they require minimal space, grow rapidly, and can thrive in containers, windowsills, or small garden plots. According to the University of Minnesota Extension, green onions tolerate a wide range of temperatures and can produce harvestable stalks in as little as three weeks from seed.

Three Proven Methods to Grow Green Onions

Choose the method that best fits your space and resources. Each approach delivers excellent results with proper care.

Growing Method	Time to Harvest	Space Required	Best For
Regrowing from Scraps	7-10 days	Small container	Quick indoor harvests
Soil Growing	20-30 days	6-8" deep container	Continuous outdoor harvest
Hydroponic System	15-20 days	Specialized setup	Year-round indoor production

Regrowing Green Onions from Kitchen Scraps (Fastest Method)

This zero-cost method transforms grocery store scraps into a continuous green onion supply. When preparing store-bought green onions, save the white root ends with 1-2 inches of the stalk attached.

Step-by-Step Regrowth Process

1. Cut green onions 1-2 inches above the roots
2. Place roots in a small glass with ½ inch of water
3. Position on a sunny windowsill (south-facing preferred)
4. Change water every 2-3 days to prevent stagnation
5. Harvest new growth when 6-8 inches tall (typically in 7-10 days)

This technique works because green onions contain meristematic tissue in their basal plate that rapidly generates new growth when provided with water and light. The Oregon State University Extension confirms this regrowth method produces edible scallions within one week under optimal conditions.

Growing Green Onions in Soil (Most Productive Method)

For larger harvests and longer-term production, soil growing delivers superior results. This method works in garden beds or containers.

Soil Growing Timeline

• Day 1: Plant seeds ¼ inch deep or sets 1 inch deep
• Day 5-7: Seedlings emerge
• Day 14: Thin seedlings to 1-2 inches apart
• Day 20-30: First harvest ready
• Ongoing: Harvest outer stalks while plant continues growing

Optimal Soil Conditions

Green onions thrive in well-draining soil with pH between 6.0-7.5. The University of Florida IFAS Extension recommends amending garden soil with 2-3 inches of compost before planting. For container growing, use a quality potting mix rather than garden soil.

Common Growing Challenges and Solutions

Understanding potential issues helps ensure successful harvests:

• Yellowing leaves: Usually indicates overwatering. Allow soil to dry slightly between waterings.
• Thin stalks: Caused by overcrowding. Maintain proper spacing (1-2 inches between plants).
• Pest problems: Onion thrips can damage plants. The University of California IPM program recommends insecticidal soap for control.
• Slow growth: Insufficient light is the most common cause. Provide at least 6 hours of direct sunlight daily.

Harvesting and Storage Tips

Harvest green onions when they reach 6-8 inches tall by cutting 1 inch above the soil line. This "cut-and-come-again" method encourages regrowth for multiple harvests. For best flavor, harvest in the morning when essential oils are most concentrated.

Store freshly harvested green onions in a glass of water in the refrigerator for up to two weeks. Alternatively, wrap them in a damp paper towel inside a plastic bag. Never wash green onions before storage, as excess moisture accelerates spoilage.

Seasonal Growing Considerations

Green onions tolerate temperatures from 20°F to 90°F but grow best between 55°F and 75°F. In colder climates, grow them in containers that can be moved indoors during frost. During summer heat, provide afternoon shade to prevent bolting. The Old Farmer's Almanac notes that green onions can survive light frosts, making them excellent for early spring and late fall planting.

Maximizing Your Green Onion Harvest

For continuous production, plant new batches every 2-3 weeks. When growing in soil, apply a balanced liquid fertilizer every 3-4 weeks to maintain vigorous growth. Never let the soil completely dry out, but avoid waterlogging which causes root rot. In containers, ensure adequate drainage holes to prevent water accumulation.

How long does it take to grow green onions from scraps?

Green onions typically show visible growth within 24-48 hours when regrowing from scraps in water, with harvestable stalks ready in 7-10 days under optimal conditions with adequate sunlight and fresh water changes every 2-3 days.

Can I grow green onions indoors year-round?

Yes, green onions grow exceptionally well indoors year-round. Place them in a south-facing window with at least 6 hours of direct sunlight daily, or use a grow light for 12-14 hours per day. Maintain temperatures between 60-75°F and water when the top inch of soil feels dry.

How often can I harvest green onions?

You can harvest green onions every 2-3 weeks using the cut-and-come-again method. Cut the outer stalks 1 inch above the soil line, leaving the inner shoots to continue growing. Most plants will produce 3-4 harvests before needing replacement.

Why are my green onions falling over?

Green onions fall over when they become too tall without sufficient light (causing them to stretch) or when overwatered. Ensure they receive at least 6 hours of direct sunlight daily and allow the top inch of soil to dry between waterings. Thinning crowded plants also helps prevent this issue.

Do green onions need full sun?

Green onions grow best with 6-8 hours of direct sunlight daily but tolerate partial shade (4-6 hours). In hot summer climates, afternoon shade prevents bolting. Insufficient light results in thin, weak stalks with reduced flavor intensity.