Can you grow new onions from kitchen scraps?
Written by
Olivia Mitchell
Reviewed by
Prof. Martin Thorne, Ph.D.You can also begin planting by simply regrowing green onions from scraps. Set down the white root ends in a glass of water by a window to catch the sun, and change the water every couple of days. New green shoots will grow within days, making them perfect for snipping. While this can be fun to do and provides rapid results for novices, it does have its limitations.
For reliable bulb development, use typical onion sets or seeds instead. Scrap regrowth is best suited for leafy greens, rather than full bulbs. I keep a jar of onion scraps by my window for quick harvesting daily. Bulb formation requires certain soil nutrients that aren't available to scraps.
Maximize your scrap harvest by choosing the right techniques! Opt for organic onions with a good root system intact. Use warm, room-temperature water and bright, but indirect, light. Regularly rotate your jars in the sun. Cut the greens when they reach about 6 inches tall, cutting off the leaves just above their white base. This method enables multiple growth cycles.
Keep the scraps on the surface of the water for some time, then plant the trimmed, rooted ends in pots with a mixture of soil and gravel. This will cause the production of greens for a much longer period. As I transfer my water-grown celery to pots on my balcony every spring, you will be able to have greens that are more thickened, growing for months before the soil has exhausted the plant.
Preparation
- Cut onions 2 inches above roots
- Choose jars with narrow mouths to support stems
- Use filtered water to prevent mineral buildup
Maintenance
- Change water every 48 hours
- Provide 4+ hours of indirect sunlight daily
- Trim yellowing leaves to encourage new growth
Troubleshooting
- Combat sliminess by rinsing roots under tap water
- Prevent mold by ensuring air circulation around jars
- Address weak growth with diluted liquid seaweed fertilizer
Combine methods for year-round harvests. Keep scraps of greens indoors throughout the winter to use as a source of nutrients. Plant sets outdoors when the soil begins to warm. With this method, you'll get a continuous supply of onions, allowing you to taste my fresh approach all year-round.
Select the methods that best align with your goals. Each gardening method brings its advantages. Scraps are a quick way to learn the basics of propagation. Sets give you an established source of reliable bulbs. Seeds will allow you to indulge your interest in exploring specialty types. Start small and increase your repertoire of techniques. Every gardener finds the method that best suits their own purposes.
Read the full article: How to Grow Onions Successfully at Home
