Green onions, also known as scallions or bunching onions, are a versatile and flavorful addition to any garden. With their crisp white bulbs and long green stalks, they offer a milder taste compared to other onion varieties. These perennials are easy to grow, requiring minimal space and care, making them perfect for both novice and experienced gardeners.
- Common Names: Scallions, Bunching onions, Spring onions
- Scientific Name: Allium fistulosum
- Plant Type: Perennial, bulb
- Plant Height: 1–3 feet
- Growing Difficulty: Easy
- Growing Time: 60 to 80 days
- Bloom Time: Spring
- Temperature: 68 to 78 degrees Fahrenheit
- Hardiness Zone: 6–9 (Find your hardiness zone here)
- Sunlight: Full Sun
- Soil pH: Acidic to neutral
- Watering Frequency: Regular watering as soil dries
- Plant Spacing: Space plants 2 to 3 feet apart
Different Methods to Grow Green Onions
Direct Sowing
Seeds are sown directly into finely-raked soil. A drill about half an inch deep is marked out, and seeds are sown thinly along the rows. The rows are then covered with soil or potting mix and watered thoroughly.
- Pros: Simpler and more straightforward. No need for transplanting, which reduces the risk of transplant shock.
- Cons: Requires well-prepared soil. May need more frequent weeding and thinning.
Sowing in Plug Trays
Seeds are sown into containers or plug trays filled with a general-purpose potting mix. A pinch of four to eight seeds is sown per module, covered with potting mix, and watered. The seedlings are transplanted into prepared soil once they have filled their modules.
- Pros: Makes efficient use of space. Allows for an earlier start to the growing season. Seedlings are protected from adverse weather conditions initially.
- Cons: Requires additional steps of transplanting. Needs more initial setup and materials (plug trays, potting mix).
Regrowing from Store-Bought Green Onions
Slice off the ends of the bulbs, keeping the roots attached. Stand the root ends in a small jar with water covering the roots but leaving the tops above water. Place in a bright window and replenish water as needed. Once shoots are at least 4 inches long, plant the root end in a pot or the ground.
- Pros: Quick and easy method. Utilizes kitchen scraps, reducing waste.
- Cons: Limited to a few harvests from each bulb. Requires eventual transplanting to soil for sustained growth.
Ideal Soil and Location Requirements
Green onions thrive in sandy, loamy, well-drained soil enriched with organic matter. They prefer a sunny, open site with consistent moisture but not soggy conditions. Ideal for containers or garden beds, they benefit from sharp drainage and full sun exposure.
When to Plant Green Onions
Green onions are best planted in late winter under cover, in spring, or in late summer for winter-hardy varieties. Start seeds indoors about eight to ten weeks before the last frost date, or direct sow in the garden once the threat of frost has passed. Transplant sprouts when the ground temperature reaches 50°F.
Growing Green Onions Outdoors
For growing green onions outdoors, direct sowing is the best method due to its simplicity and minimal handling of plants. Here’s a step-by-step guide to help you grow green onions in your garden:
- Choose a sunny spot. Select a location that receives full sun for at least six hours a day.
- Prepare the soil. Ensure the soil is well-drained and enriched with well-rotted organic matter like compost. Aim for a slightly acidic to neutral pH.
- Mark out rows. Create rows about 4 inches (10 cm) apart. This spacing allows for adequate air circulation and growth.
- Drill depth. Make a shallow drill about 0.5 inches (1 cm) deep in each row.
- Sow seeds thinly. Scatter the seeds thinly along the drills to avoid overcrowding.
- Cover seeds. Lightly cover the seeds with soil or potting mix.
- Water thoroughly. Water the rows well to ensure the soil is moist but not waterlogged.
- Label rows. Use markers to label each row to keep track of your planting.
- Maintain moisture. Keep the soil consistently moist, especially during dry weather, to promote healthy growth.
- Thin seedlings. Once the seedlings are a few inches tall, thin them to about 2-3 inches (5-7 cm) apart to give each plant enough space to grow.
Growing Green Onions Indoors
Growing green onions indoors is entirely possible and can be done effectively using containers or plug trays. Here’s a step-by-step guide to help you grow green onions indoors:
- Choose a container. Use pots with drainage holes to prevent waterlogging.
- Fill with potting mix. Use a quality, well-draining, organic potting mix.
- Sow seeds. Plant seeds about 1/4 inch deep in the potting mix.
- Water thoroughly. Keep the soil consistently moist but not soggy.
- Place in bright light. Position the container by a bright window or under grow lights for at least six hours of direct sunlight daily.
- Maintain temperature. Ensure indoor temperatures are between 68-78°F for optimal growth.
- Thin seedlings. Once seedlings are a few inches tall, thin them to about 2-3 inches apart to give each plant enough space to grow.
- Water regularly. Continue to keep the soil moist, especially as the plants grow.
- Harvest when ready. Green onions are ready to harvest when they are 6 to 8 inches tall and as wide as a pencil. Cut leaves as needed or pull the whole plant.
Green onions can be sown in late summer to give one of the earliest harvests next spring.
Caring for Green Onions
- Keep the soil moist: Green onions have shallow roots, so it's essential to water them regularly. Ensure the soil is consistently moist but not waterlogged to promote healthy growth.
- Weed control: Remove weeds as soon as they appear to prevent them from competing with your green onions for nutrients and water. This will help your plants thrive.
- Fertilize wisely: Use a balanced fertilizer, preferably one high in nitrogen, such as fish emulsion. This will keep your green onions green and growing vigorously.
- Watch out for pests: Common pests like cutworms, onion maggots, and aphids can affect green onions. Use row covers to protect seedlings and rotate crops to manage pest populations.
- Harvesting tips: Green onions are ready to harvest when they are about 6 to 8 inches tall and as wide as a pencil. You can cut the leaves as needed or pull out the whole plant. Fresh leaves will keep in the refrigerator for about a week.
Common Challenges With Green Onions
Green onions are a very resilient plant, making them an excellent choice for both novice and experienced gardeners. They are relatively easy to grow, requiring just a sunny spot and well-drained soil. In my experience, they fit perfectly in small garden spaces or even containers, and they can be harvested in as little as eight weeks. Their ability to regrow from root ends also adds to their appeal, allowing for multiple harvests from a single planting.
However, growing green onions isn't without its challenges. Common pests like cutworms, onion maggots, and aphids can pose problems. Birds may also peck at emerging seedlings, especially early in the season. Diseases such as mildew and rust can occur if the growing conditions are not ideal. Regular monitoring and preventive measures, like using row covers and ensuring adequate sunlight and moisture, can help mitigate these issues.
Safety of Green Onions for Pets
Green onions are toxic to cats, dogs, and other pets. If you suspect your pet has ingested green onions, contact the ASPCA 24-hour hotline immediately for assistance.
Frequently Asked Questions
Can green onions be grown in containers?
Yes, green onions can be grown in containers. Use pots with drainage holes and fill them with a well-draining, organic potting mix. Ensure the container is placed in a sunny spot and water regularly to keep the soil moist.
How often should I water green onions?
Green onions require consistent moisture. Water them regularly to keep the soil moist but not waterlogged. During dry weather, increase the frequency of watering to prevent the plants from bolting and to promote healthy growth.
What pests commonly affect green onions?
Common pests include cutworms, onion maggots, and aphids. To manage these pests, use row covers to protect seedlings and rotate crops annually. Regular monitoring and prompt action can help keep pest populations under control.
When is the best time to harvest green onions?
Green onions are ready to harvest when they are about 6 to 8 inches tall and as wide as a pencil. You can either cut the leaves as needed or pull out the whole plant. Freshly harvested green onions can be stored in the refrigerator for about a week.
