How to Grow Green Onions Indoors
By Desmond Hale · July 5, 2026 · 5 min read
Quick answer
Stand green onion root ends in an inch of water on a bright windowsill and they regrow in 7–14 days. Change the water every two days, or pot them into soil after the first regrowth for months of harvests.
The water jar method
- Cut green onions about an inch above the white root base and keep the bases.
- Stand them upright in a glass with an inch of water — roots submerged, white stems mostly above water.
- Place in bright indirect light and change the water every two days.
- Harvest the green tops once they reach 6 inches, leaving the base in place.
The soil method for long-term supply
Plant bases an inch deep in a 4–6 inch pot of potting mix, one inch apart. Water when the surface dries, feed monthly at half strength, and shear the tops to two inches whenever you need onions.
Growing from seed
Scatter seed thickly in a 6-inch pot, cover lightly, and keep moist. Expect 8 weeks to the first cut, but a seed-grown pot stays productive for a year or more.
Light and placement
Green onions are among the few edibles that tolerate bright indirect light. A north-facing kitchen window is enough, which makes them perfect for apartments with poor sun.
Frequently asked questions
How many times can you regrow green onions in water?
Two or three times before growth becomes thin and pale. Transfer them to soil to keep harvesting beyond that.
Why do my green onions smell bad in the jar?
The water is stagnant. Change it every two days, rinse the roots, and keep the white stems above the waterline.
