Green onions, also known as scallions or spring onions, are among the most versatile and widely used ingredients in home cooking. Their mild, slightly peppery flavor complements a wide range of dishes—from stir-fries and soups to salads and omelets. But what truly makes them a standout ingredient is how easy they are to regrow right in your kitchen from leftover scraps.
If you've ever found yourself tossing the white ends of green onions into the compost bin, you're missing out on one of the simplest and most satisfying gardening experiences available. With just a glass of water, some sunlight, and a little patience, you can regenerate an endless supply of green onions without stepping foot into a garden center.
In this guide, you'll learn how to grow green onions from kitchen scraps, why it works, how to care for them indoors or outdoors, and how to keep them producing again and again. Whether you're an urban gardener, a homesteader, or simply a curious home cook, this method adds a sustainable and rewarding element to your kitchen routine.
Why Grow Green Onions from Scraps?
Growing green onions from kitchen scraps isn’t just a fun experiment—it’s a practical way to reduce waste and stretch your grocery budget.
1. Cost-Effective
A single bunch of green onions can produce multiple harvests. Instead of buying new bunches each week, you’ll always have fresh greens ready to snip.
2. Zero-Waste Gardening
Using the root ends you’d normally discard turns food waste into food again. It’s one of the most accessible forms of regenerative gardening.
3. Beginner-Friendly
No special tools, soil amendments, or gardening experience required. This project is perfect for anyone—even kids can participate and learn.
4. Fast Results
You can see visible regrowth in just a couple of days. In less than a week, your green onions will be ready for a light trim.
5. Grows Indoors or Outdoors
Green onions thrive in a sunny kitchen window, on a balcony, or in a garden bed. The flexibility makes them ideal for all living spaces, including apartments.
How Green Onions Regrow Themselves
Green onions belong to the allium family, which also includes garlic, leeks, and regular onions. Their structure includes a white bulb base, which houses a cluster of roots and a central growth point called the meristem. This region contains dormant cells capable of regenerating new green shoots when placed in the right conditions.
So when you cut off the tops of your green onions and leave at least 1–2 inches of the white base with roots intact, you're preserving the part of the plant capable of new life. With water and light, this base becomes the engine of regrowth.
What You’ll Need to Get Started
Regrowing green onions doesn’t require a green thumb or expensive equipment. You likely already have everything you need.
Supplies:
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A bunch of store-bought green onions (with white root ends intact)
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A clean glass or jar
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Fresh water
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A sunny windowsill or well-lit area
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(Optional) Potting soil and a container or outdoor space for planting
Optional for long-term growth:
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Organic potting mix or compost-rich soil
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6-inch deep container with drainage holes
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Liquid fertilizer (diluted)
Step-by-Step Instructions: Regrowing in Water
This method is quick, clean, and perfect for indoor kitchens.
Step 1: Prepare the Scraps
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Cut the green tops off the onions, leaving about 1 to 2 inches of the white bulb and roots.
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Use the green parts in your cooking, but don’t discard the root bases.
Step 2: Place in Water
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Fill a small jar or glass with about 1 inch of water.
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Place the root ends into the water with the root side down and the cut side up.
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Arrange them so they’re standing upright. You can lean them against the side of the jar or use a rubber band to group them.
Step 3: Set in Sunlight
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Place the jar on a sunny windowsill, ideally one that receives 6 or more hours of light per day.
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A south-facing window is ideal, but any bright indoor spot works.
Step 4: Change Water Regularly
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Change the water every 1 to 2 days to prevent bacterial growth and keep the roots healthy.
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Rinse the jar if you notice slime or discoloration.
Step 5: Watch Them Grow
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Within 2–3 days, green shoots will begin to emerge from the top.
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In 5 to 7 days, you’ll have usable greens, and within two weeks, full-length scallions.
You can continue growing them in water, but eventually the roots may weaken. For longer life, transplanting to soil is the next step.
Transitioning to Soil: For Continuous Growth
While water regrowth is great for short-term harvests, green onions thrive longer and grow stronger in soil.
Step 1: Choose a Container or Garden Spot
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If planting indoors, choose a container at least 6 inches deep with drainage holes.
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Outdoors, choose a well-drained, sunny spot in your garden or raised bed.
Step 2: Use Good Soil
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A mix of potting soil and compost works well.
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Avoid dense, clay-rich soils that may retain too much moisture.
Step 3: Plant the Onions
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Make holes in the soil about 2 inches apart.
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Insert the root ends about 1 inch deep, with the green shoots pointing up.
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Gently press the soil around the base to secure them.
Step 4: Water Gently
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Water thoroughly after planting, then keep the soil consistently moist but not soggy.
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Water when the top inch of soil begins to feel dry.
Step 5: Provide Sunlight
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Green onions need 6+ hours of sunlight per day for healthy growth.
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If growing indoors, place them near a sunny window or use grow lights.
With proper care, your transplanted green onions can regrow multiple times and even produce new shoots from the same base.
Harvesting Your Homegrown Green Onions
One of the best things about green onions is how forgiving and generous they are when it comes to harvesting.
How to Harvest:
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Wait until the greens are at least 6–8 inches tall before cutting.
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Use clean scissors or shears to snip off the green tops, leaving at least 1 inch above the soil or water line to allow regrowth.
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Avoid cutting all the way to the base—leaving some growth ensures the plant can continue photosynthesizing.
Frequency:
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You can usually harvest every 1 to 2 weeks, depending on light and temperature.
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The same plant can regrow 3–5 times before slowing down.
Tips for Stronger, Tastier Green Onions
As with all gardening, attention to detail helps your plants thrive.
1. Don’t Overcrowd
If growing in containers, give each plant space for roots and airflow. Overcrowding reduces vigor and increases the risk of disease.
2. Fertilize Occasionally
If your plants start to pale or slow down, a diluted organic liquid fertilizer (like fish emulsion or compost tea) can boost growth.
3. Rotate or Refresh Water
Even with regular water changes, slimy roots may signal a need to switch containers or transfer to soil.
4. Pinch Off Flower Stalks
If your green onions begin to flower, snip the stalks early. Flowering redirects energy from leaf production, which reduces the quantity and quality of edible greens.
Growing Green Onions Outdoors from Scraps
Once the risk of frost has passed, you can plant your regrown green onions directly into a garden bed. They're low-maintenance and make excellent companions for other vegetables like carrots, beets, or lettuce.
Outdoor Considerations:
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Space plants 2–4 inches apart in rows.
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Water regularly, especially in hot or windy weather.
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Mulch around the base to retain moisture and prevent weeds.
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Green onions are frost-tolerant and can often be grown through cool seasons in mild climates.
How Long Will They Last?
Green onions grown from scraps are resilient but not immortal. Most will produce 3–5 harvests in water and more if transplanted to soil.
Eventually, the root base may lose strength or succumb to decay. At that point, it’s time to compost the old plant and start again with a new bunch. The cycle continues—with no trip to the store required.
Troubleshooting Common Problems
Growing green onions from kitchen scraps is simple, but occasional issues may arise.
| Problem | Cause | Solution |
|---|---|---|
| Wilting or drooping shoots | Lack of light or poor root development | Move to a sunnier spot or transplant to soil |
| Slimy roots | Water not changed frequently enough | Change water every 1–2 days and rinse roots |
| No regrowth | Root base cut too short or damaged | Make sure to leave at least 1 inch of white base |
| Yellowing tips | Nutrient deficiency or water stress | Fertilize lightly and maintain even watering |
If you're growing in soil and see these problems, check for drainage issues or overwatering.
Creative Ways to Use Your Homegrown Green Onions
Growing your own green onions opens up culinary possibilities.
Fresh Uses:
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Sprinkle chopped greens on ramen, stir-fries, or grilled meats
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Add to scrambled eggs, quiches, or frittatas
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Mix into dips, sauces, or compound butters
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Use as a garnish for soups, stews, and chili
Preservation Tips:
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Chop and freeze in small containers for easy use later
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Dehydrate and store in jars for homemade onion flakes or powder
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Blend with herbs and oil to create green onion pesto or chimichurri
Final Thoughts
Learning how to grow green onions from kitchen scraps is one of the simplest and most satisfying introductions to sustainable gardening. It transforms waste into life, saves money, and keeps your cooking stocked with fresh, flavorful greens year-round.
Whether you’re regrowing on a windowsill or planting a mini-scallion patch outdoors, the process is easy to master and endlessly repeatable. With each new cycle, you deepen your connection to your food and gain confidence in your ability to grow more from less.
The next time you're cooking and reach the end of a bunch of green onions, don’t toss those roots in the trash. Place them in water, give them a sunny seat, and watch them come back to life—again and again.