Many vegetables can be cultivated from scraps that might otherwise end up in the bin. Regrowing onions from leftover pieces offers a fantastic opportunity for those looking to save money and grow their own food from waste.
Onions are a must-have in many kitchens and can be easily regrown in a pot on your windowsill or outdoors with just a bit of soil. Alternatively, you can sprout them in water without any soil at all.
By growing onions, you can explore various bulb types that may not be available in stores. There are numerous onion varieties for every dish. Sprouting your chosen onions allows you to discover your favorites and maintain a continuous supply.
Harvesting onions typically occurs in summer and fall
Regrowing Onions from Scraps in 4 Simple Steps
It’s quite straightforward to regrow onions from scraps using just a small section of onion. This can be done with store-bought onions or ones from your own garden.
- Slice off the root end of an onion, about half an inch thick.
- Place it root-side down in a pot filled with soil, then cover it lightly with soil.
- Keep the soil damp, and within three weeks, the onion scraps will start producing shoots.
- Harvest the shoots as onion greens or transplant the rooted onion into your garden or a larger container.
Garden writer and speaker Jo Ellen Meyers Sharp advises that you can regrow onions anytime you have scraps. They thrive on a sunny windowsill and can be moved outdoors later.
You can also skip the indoor pot entirely and plant onions directly in the garden. Simply push the root end down into the soil and cover it lightly, watering to promote sprouting. The onion can grow right where it’s planted.
Onions are essential in various global cuisines
Growing Onions from Scraps in Water
You can also grow onions in water without the need for soil or compost. The process is similar to the one described above.
Take the root end of the onion and place it in a bowl with one or two inches of water, ensuring it’s sitting in the water but not submerged. Set the container on a sunny windowsill to encourage sprouting.
Alternatively, you can use cocktail sticks to hold the onion above a jar of water, allowing the base to touch the liquid. Change the water regularly to keep it fresh, and roots should begin to sprout within a week. You can then plant the sprouted onion.
Scallions are easy to grow in water
Regrowing Green Onions from Scraps
Green onions, or scallions, are also very easy to grow from kitchen scraps. Like bulb onions, they can be sprouted in soil or water.
To grow green onions in water, leave about two inches of the white bulbs with the roots intact. Place these cut ends root-down in a glass filled with enough water to cover the roots. Set it on a sunny windowsill, and within a few days, you’ll see green shoots. Change the water regularly to prevent discoloration.
Once the shoots are around five inches tall, it’s time to plant them in the ground or a container. They can’t thrive in just water for long, or the greens will become weak.
Onions flourish well in containers
Best Time for Growing Onions from Scraps
Regularly sprouting onions from scraps can provide you with a steady supply for various culinary uses. With a bit of planning, you can sprout onions for both bulbs and quick greens. You can sprout for greens any time, but growing onions to maturity is best during specific seasons.
Spring and early summer are ideal for planting sprouted onions outdoors, as they need six to seven hours of sunlight daily to develop into robust bulbs. While you can sprout onions in the fall and winter, they are more prone to bolting in spring.
Samuel J Schmitz, a horticulturist at The Gardens at Ball in West Chicago, Illinois, notes, “Onions thrive in full sun and warmth. Plant them in well-tilled soil in a bright, sunny area for success.”
You can grow onions indoors year-round, using artificial lights if necessary. For those with limited outdoor space, growing onions in containers is a great option.
Bunching onions can be sprouted multiple times
Time Required to Grow Onions from Scraps
Patience is needed when growing onions from scraps if you want the sprouted piece to develop into a full onion. After starting an onion on a windowsill, expect about 90 to 120 days until harvest.
If you’re sprouting for greens, the wait is much shorter. Scallions can be ready for harvesting in under six weeks. Green onions can be regrown multiple times from the same root, both in soil or water, typically up to five times before growth weakens.
Can I Plant a Whole Sprouted Onion?
If you have a store-bought onion that’s sprouting, you can plant it whole, but you won’t get new onions from it. Planting a whole onion will yield green onion sprouts.
For new onions, it’s better to separate the sprouts from the onion layers, as each sprout can grow into a new onion. You can either place these sprouts in water until roots form or plant them in soil about 1 to 1.5 inches deep.
