Want to reduce waste and enjoy fresh, homegrown produce?
You should try regrowing green onion tops from your kitchen scraps!
In fact, I bet that’s why you’re here today. 😉
We’ll walk you through the simple steps to transform onion remnants into a continuous supply of green onions right on your windowsill.
First, Not All Onion Scraps Are Good Candidates
Not every piece of onion scrap will give new life. For the best outcomes, look for those with a bit of the white part and roots still attached.
These white bulbs are where the magic happens. Onion bottoms with a small cluster of white roots dangling from them stand a higher chance of sprouting new green shoots.
It’s the blend of these white roots and the moist cut end that become the cradle for new growth.
Prepare the Scraps and Root in Water
Once you have a good candidate, trim away any spoiled layers from the white bulbs (if there are any). Be careful to leave a portion of the roots attached.
Place the white part, root side down, into a small glass or Mason jar filled with water. The water should cover the roots fully but leave the top part exposed.
Change the water every day to prevent overly dingy water and root rot. This small act can significantly boost the new growth process.
After 2-3 weeks, you should see new roots and green shoots emerging.
Potting and Soil Requirements
At this point, you’ll want to give your green onion roots more nutrients, which equals soil. A small pot should be fine. Just ensure that the onion has enough room to grow, and be sure the pot has adequate drainage.
Use well-draining, nutrient-rich soil. Raised bed or “container” soil works well and will give your onion bulbs a head start.
Transplant from the jar to the pot gently, paying careful attention to the roots. (You don’t want to disturb them too much.)
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Positioning and Sunlight
Now, the best thing for their growth is to position them properly. Place your potted onions in an area that gets adequate sunlight like a sunny windowsill, where they can bask in full sun for a long time every day.
This will ensure they receive enough sunlight to sprout new leaves.
Sunlight triggers photosynthesis in the green parts, powering the whole plant to produce new green onions.
Watering and Care
Watering your newly rooted onion scraps sets the foundation for healthy new growth. Keep the soil moist but not soggy, as excessive moisture can lead to rot.
Initially, check the moisture level daily by touching the soil. If the top feels dry, it’s time to add a little bit of water.
Remember, the goal is to keep the environment stable for those tender white roots to flourish without stress.
Over time, as new green shoots emerge and strengthen, you’ll find the sweet spot in your watering routine.
Though you should water based on soil moisture, a general rule of thumb is to water three times per week.
Harvesting Your Green Onions
After weeks of nurturing, your green shoots will mature, heralding the time for harvest.
The cut-and-come-again method is a great way to harvest green onions (or scallions) without needing to uproot the entire plant.
Here’s how you can do it:
1. Wait for Growth: Allow your green onions to grow to at least 6 inches in height before harvesting. This usually takes a few weeks after planting.
2. Selective Harvesting: When the green onions have reached a decent height, select the ones you want to harvest. Choose the outer ones first, leaving the inner ones to continue growing.
3. Cutting Technique: Use a pair of sharp scissors or a knife to cut the green onions about 1-2 inches above the soil level. Make sure to cut straight across rather than at an angle. This allows for easier regrowth.
4. Leave Roots Intact: When cutting, leave the white bulb and the roots in the soil. These parts will regrow even more green shoots!
5. Repeat as Needed: As your green onions continue to grow, repeat the process whenever you need more. You can generally harvest them every few weeks.
By following these steps, you can enjoy a continuous supply of fresh green onions from your kitchen scraps using the cut-and-come-again method.
Frequently Asked Questions
How long does it take to grow an onion from scraps?
Green onion tops can regrow from kitchen scraps within a few days to a couple of weeks, producing new shoots that can be harvested as needed.
In order to reach that ideal height of 6 inches before starting the “cut and come again method,” you should probably wait at least 3 weeks before your first harvest.
Can I plant onions that have sprouted in my pantry?
If onions have sprouted in your pantry, they are good candidates for re-planting. Just know that you won’t get another big bulb or “head” of onion.
Replanting a sprouted onion is only good for growing green onion tops.
To transplant into your garden, simply plant the sprouted onions in soil with the sprout pointing upwards, covering them lightly with soil.
Keep the soil consistently moist and place the container in a sunny location for optimal growth.
How many times can you regrow onions?
You can regrow green onions multiple times using the cut-and-come-again method, typically harvesting the green tops several times before they exhaust their regrowth capacity.
(The vigor of the new shoots will dwindle eventually.)
If you’re looking for number, I’d say you can expect three to four cycles of “cut and come again” harvesting before needing to start fresh.
