How to Grow Scallions Indoors From Scraps

Scallions — also called green onions or spring onions — are the single easiest vegetable to grow indoors, and you can start with nothing more than the root ends you would normally throw away. Stand those white root bases in a glass of water on a sunny windowsill and they begin regrowing within a day or two, giving you fresh green tops to snip in under a week. With a little soil and the right light you can keep a small scallion patch producing for months, cutting and regrowing the same plants again and again. This guide walks through both the quick water method and the longer-lasting soil method step by step, explains how much light scallions actually need, how to harvest so they keep coming back, and how to troubleshoot the common problems of sliminess, thinning, and stalling that cut short most windowsill attempts.

In this guide

1. What You Need to Get Started
2. Method 1: Regrowing Scallions in Water
3. Method 2: Growing Scallions in Soil
4. How Much Light Scallions Need
5. Harvesting So They Keep Coming Back
6. Troubleshooting Indoor Scallions
7. Keeping a Continuous Supply Year-Round
8. Frequently Asked Questions

What You Need to Get Started

The beauty of growing scallions indoors is the near-zero cost. You need a bunch of store-bought scallions (or seeds, if you prefer starting from scratch), a small jar or glass for the water method, or a pot with drainage and potting mix for the soil method. A bright windowsill is essential; a small LED grow light helps in darker homes. That’s it. The roots and white bases you’d discard after using the green tops are your free starter material.

Choose scallions that still have intact, healthy-looking roots at the base — these regrow far better than trimmed ones. When you buy a bunch, plan to use the green tops in cooking first, then put the white root ends to work regrowing. Firm, fresh root ends with white, unbruised bases give the best results; slimy or yellowing bases are more likely to rot than regrow.

Method 1: Regrowing Scallions in Water

The water method is the fastest gratification in all of indoor gardening — you’ll see visible growth overnight. It’s perfect for a quick supply and a great project for kids or beginners.

1. Cut your scallions about 1 to 2 inches up from the root base, keeping the white bulb portion and all the roots intact. Use the green tops for cooking.
2. Stand the root ends upright in a small glass or jar, roots down, with enough water to cover the roots and the bottom half-inch of white but not the cut tops. A narrow jar keeps them upright; a rubber band around the bunch helps too.
3. Place the jar on a bright windowsill that gets at least 6 hours of light. A south- or west-facing window is ideal.
4. Change the water every 1 to 2 days. Fresh water is the single most important step — stale water turns slimy, smells, and rots the roots.
5. Watch the green shoots regrow from the center of each white base. You’ll often see new growth within 24 to 48 hours.

In about 7 to 10 days the green tops will have regrown enough to harvest again. You can usually get 2 to 4 good cycles from water alone before the bases start to weaken and the new growth gets thin and pale — that’s the sign the plant has used up its stored energy and needs soil to keep going.

Method 2: Growing Scallions in Soil

For a longer-lasting, better-tasting supply, move your scallions into soil — or start them there directly. Soil-grown scallions feed themselves through their roots, so they stay productive for many months and develop fuller flavor than water-only plants.

1. Fill a pot at least 4 to 6 inches deep with quality potting mix. Make sure it has drainage holes.
2. Plant the white root ends about 1 inch deep, roots down, spacing them an inch or two apart. You can plant a whole row or cluster in one pot.
3. Water until the soil is evenly moist but not soggy, then place the pot in bright light — a sunny windowsill or under a grow light.
4. Keep the soil consistently moist, watering when the top half-inch begins to dry. Scallions like steady moisture but hate sitting in water.
5. Once established, feed every few weeks with a diluted balanced liquid fertilizer to keep the green growth lush.

You can also start scallions in soil from seed for a fresh, vigorous crop — sow seeds a quarter-inch deep, keep moist, and thin seedlings to about an inch apart. Soil-grown plants will produce for months with regular harvesting and the occasional feeding. If you enjoy growing edibles in small spaces, our ebb and flow hydroponics guide covers another soil-free way to grow greens indoors.

How Much Light Scallions Need

Light is what separates thriving scallions from sad, floppy ones. Scallions want at least 6 hours of bright light per day, and more is better. A south-facing window is the gold standard indoors; a west window is a solid second choice. East windows and north windows usually don’t provide enough light on their own — plants grown there stretch, lean toward the glass, and produce thin, pale tops.

If your home is short on bright windows, a basic LED grow light run 12 to 14 hours a day keeps scallions compact, green, and productive year-round. Position the light a few inches above the tops and raise it as the plants grow. Rotate water jars or pots a quarter turn every couple of days so the plants grow straight instead of bending toward a single light source. Good light also keeps the flavor sharp; under-lit scallions taste milder and watery.

Harvesting So They Keep Coming Back

The trick to a continuous supply is cut-and-come-again harvesting. Instead of pulling the whole plant, snip the green tops with scissors, leaving about an inch of green above the white base. The plant regrows fresh shoots from that base over the next week or two, giving you repeated harvests from the same roots.

Harvest the outer or tallest leaves first and take only what you need, so the plant always keeps enough green to power regrowth. Regular cutting actually encourages more growth, much like trimming many herbs. With water-grown scallions, expect vigor to fade after a few cycles; with soil-grown plants, consistent harvesting and occasional feeding can keep a pot productive for several months before you start a fresh batch from new scraps.

Troubleshooting Indoor Scallions

The most common problem with the water method is sliminess and a sour smell, caused by infrequent water changes. Refresh the water every day or two and rinse the roots gently when you do. If the white bases turn mushy or brown, they’ve rotted — discard them and start with fresh root ends, keeping the water level lower so only the roots and a sliver of white are submerged.

Thin, pale, floppy new growth almost always means not enough light; move the plants to a brighter window or add a grow light. If regrowth slows or stops in water after a few cycles, the scraps have exhausted their stored energy — transplant them into soil or start fresh. Yellowing tips on soil-grown plants can signal a need for light feeding. Scallions are remarkably forgiving, so most issues trace back to just two things: dirty water and dim light. Fix those and you’ll have a near-endless kitchen supply. For more compact edible growing ideas, explore our urban gardening guides.

Keeping a Continuous Supply Year-Round

The secret to never buying scallions again is staggering your plantings. Rather than starting one big batch and watching it fade all at once, start a new jar or pot of scraps every week or two. With three or four containers at different stages, you’ll always have some plants at peak harvest while others are just getting going. This rotation also lets you retire tired water-grown scraps into soil — or the compost — without ever running short of fresh green tops for the kitchen.

Temperature matters too. Scallions are cool-season plants at heart and grow happily at normal indoor temperatures of 60°F to 75°F. They don’t need warmth the way tomatoes or peppers do, which makes a bright but cool windowsill — even a chilly kitchen window in winter — perfectly suited to them. Avoid placing them right next to a hot radiator or heating vent, which dries them out and can scorch the delicate tops. A spot with steady, moderate warmth and good light will keep them producing through every season, including the depths of winter when fresh herbs are most welcome and most expensive at the store.

Finally, harvest little and often. Scallions are at their best snipped fresh and used the same day, so treat your windowsill patch as a cut-as-you-need supply rather than a one-time crop. The more regularly you trim, the more vigorously the plants push new growth, and the more value you wring out of those once-discarded root ends.