Growing Scallions From Bulbs: Regrow Green Onions in 2 Weeks

How to grow scallions from bulbs is the easiest gardening hack you’ll ever try—no dirt, no mess, just fresh green onions in 2 weeks. 🌱 I’ve done this a dozen times since my first failed attempt (too much water, ugh), and now I keep a jar of regrowing scallions on my counter year-round. The secret? A shallow container, patience, and remembering that roots need air almost as much as water.

You only need three things: a bulb from the grocery store (save the roots!), a shallow dish with water (about ½ inch deep), and a sunny windowsill or grow light.

The bulbs stay fresh longer if you trim the green tops back to 1 inch before soaking—this focuses energy on root growth. Change the water every 2-3 days to prevent rot, and watch those white roots thicken within 5-7 days.

By day 14, you’ll have 3-4 inches of fresh green ready to snip for cooking, and the bulb itself stays edible too. The taste is just as sharp as store-bought, but with zero waste. This method works indoors, on balconies, or even in a tiny kitchen nook—no garden required.

The only real mistake? Letting the water get too deep (roots rot fast) or forgetting to refresh it (smells bad, slows growth).

Once you master this, try growing from scraps year after year. I’ve kept the same bulb producing for over a month with occasional water changes, and it’s become my go-to for quick, chemical-free greens. The best part? You’ll never buy scallions again—just save the bulbs and regrow them forever.

What you need

Step-by-Step instructions for regrowing scallions from store-bought bulbs

Here's the foolproof method I use to get fresh green onions in just two weeks—no soil, no mess, and zero gardening experience required.

Choose firm, fresh scallions with roots still attached—look for the white bulb base that feels plump, not shriveled. The roots should be about ½ inch long and white, not brown or dried out. Cut off the green tops about 1 inch above the bulb using a sharp knife. This triggers root regrowth while keeping the plant focused on producing new greens.

Real talk: if the roots are already brown and mushy, skip it. You won't get regrowth from a bulb that's already decomposing. I like to save the green tops for immediate cooking—they'll stay fresh in the fridge for a few days while the roots regrow.

Fill a shallow dish or small bowl with about 1 inch of room-temperature water. Place the scallion bulbs in the water so the roots are submerged but the bottom of the bulb remains above the waterline. You want the roots to drink up moisture while the bulb stays dry enough to prevent rot. I use a clear glass so I can watch the roots grow—it's weirdly satisfying.

Change the water every 2-3 days to prevent bacterial growth. You'll notice tiny white root hairs sprouting within 3-5 days. If the water gets cloudy before then, dump it and refresh. Cloudy water means bacteria is setting in and could rot your bulbs before they regrow.

Set the dish in a spot with bright, indirect light—think kitchen windowsill or under a grow light. Direct sunlight will scorch the new greens, so avoid south-facing windows without a sheer curtain. You'll see new growth emerging from the top of the bulb within 5-7 days. These are your first true leaves, signaling the plant is actively growing.

Keep the water level consistent—never let the bulbs sit dry, but don't submerge them completely. The bottom of the bulb should always stay above water. Within 10-14 days, you'll have 3-4 inches of fresh green onion ready to harvest. I like to trim about ½ inch from the top to encourage more growth.

When the greens reach about 4-6 inches tall, snip them just above the bulb with clean scissors. This prevents crushing the tender new growth. Rinse the greens under cold water to remove any water spots, then pat dry gently with a paper towel. Store them in a sealed container in the fridge for up to 1 week, or use immediately in recipes.

After harvesting, return the bulb to the water system. You'll get 2-3 additional harvests this way before the bulb peters out. Each time, the greens will be slightly smaller, but still fresh and flavorful. When the bulb finally stops producing, compost it—it's done its job.

If your scallions develop yellow leaves, they're getting too much light or not enough water. Move them to a shadier spot and check the water level daily. Brown tips? That's usually from fluoride in tap water. Switch to filtered or distilled water for the final week of growth to keep the greens crisp and vibrant.

Mold or slimy water means bacteria is taking over. Dump the water immediately, rinse the bulbs with clean water, and start fresh. I've regrown scallions this way dozens of times—once you get the hang of it, you'll never buy green onions again. The best part? No soil, no pests, and zero maintenance beyond a quick water change.

Tips & tricks for perfect scallion regrowth

Here's what nobody tells you about turning grocery store scallions into a never-ending herb supply—these are the secrets that make the difference between wimpy sprouts and lush, flavorful regrowth.

Bulb Selection is Everything: The key to success starts in the produce aisle. Look for scallion bulbs with roots that are white and firm, not brown or shriveled. The bulb itself should feel heavy for its size—this indicates moisture retention. I've found that organic scallions often have healthier roots, but conventional ones work too if they're fresh. Confession: I skipped this step for years and wondered why my regrowth always failed.

Root Health Check: Before cutting those green tops in Step 1, give your scallion bulbs a quick soak in cool water for 10 minutes. This revives any slightly wilted roots and helps them recover faster. After soaking, gently squeeze out excess water—you want damp, not dripping, roots. This simple step can add 2-3 days to your regrowth timeline by preventing early stress on the bulb.

Lighting Strategy: Bright indirect light is non-negotiable in Step 3, but here's the pro move: if you're using a windowsill, rotate your dish 180 degrees every 24 hours. This prevents the greens from leaning toward one light source and growing lopsided. For even better results, place your regrowing scallions under a grow light 6-8 inches away for 12 hours daily—this mimics natural sunlight perfectly and speeds up growth by 30%.