Yes, you can regrow store-bought green onions, also known as scallions, using the white root end typically discarded after use. This is possible because the plant’s basal plate, where the roots emerge, remains alive and capable of producing new green shoots. Utilizing this living root structure allows you to establish a continuous, fresh supply right in your kitchen. The initial regrowth method is simple and relies only on water to stimulate growth.
Regrowing Green Onions in Water
The quickest method for immediate regrowth involves placing the root ends in a shallow glass of water. Cut the green stalks from the white bulb, leaving about one to two inches of the white section intact, along with the wispy roots. Stand these white bases upright in a small glass or jar, adding just enough tap water to cover the roots and the very bottom of the white bulb.
Place the container on a sunny windowsill, as the plant needs ample light to fuel new growth. Within a day or two, new green shoots will emerge from the center. To prevent rot or mold, the water must be changed every one to three days, ensuring a fresh, clean supply. While this method provides a fast yield, regrowth will eventually slow, and the flavor will become less robust because plain water lacks long-term nourishment.
Transplanting for Long-Term Growth
For a more sustainable and flavorful supply, transplant the regrowing onion bases into soil once new roots have formed. Soil offers a more stable and nutrient-rich environment than water alone. The soil contains essential minerals and organic matter crucial for developing a strong root system and sturdy leaves. This transfer extends the plant’s productive lifespan beyond the water-only method.
To transplant, select a container with good drainage and fill it with a quality, well-draining potting mix. Plant the white bulb section so the roots are fully covered and the top of the white portion is just below the soil surface. Water the container thoroughly to settle the soil around the roots. Keeping the soil consistently moist, but not saturated, is important for continuous growth and root establishment. This results in a more robust plant with thicker, tastier green stalks.
Harvesting Techniques and Longevity
Proper harvesting maximizes the yield and prolongs the life of your regrown onions. When the green stalks reach a useable height, typically six to eight inches, snip only the green parts with scissors or a knife. Leave the white base and the roots undisturbed in the soil or water so the plant can continue to photosynthesize and regrow. Always cut about one inch above the base to ensure the structure can regenerate effectively for the next harvest.
You can expect multiple successful harvests from a single base, typically three to five cutting cycles. After this period, the plant’s vigor and flavor will decrease due to the depletion of stored energy. In some cases, the plant may begin to “bolt,” sending up a flower stalk; this signals the end of the best harvesting period as the plant shifts energy to seed production. If the growth becomes thin or pale, replace the old base with a new one from a fresh bunch of onions.