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Grow guide 6 min read

How to Regrow Vegetables from Kitchen Scraps (That Actually Work)

Some of the easiest food to grow starts in your kitchen bin. With nothing more than a glass of water and a sunny windowsill, you can regrow green onions, leafy greens, and fresh herbs from the scraps you would normally throw away. It feels like magic the first time, and it is a brilliant, no-risk way to start growing.

Let us be honest, though: not every scrap regrows into something worth eating. This guide sticks to the ones that genuinely work.

Green onion scraps regrowing roots in a glass of water
A glass of water and a bright windowsill is all most scraps need to start.

The basic setup (works for almost everything)

  1. Keep the root end or the base of the vegetable, roughly 3 to 5 cm.
  2. Stand it root-down in a glass or jar with just enough water to cover the roots, not the whole piece.
  3. Put it on your brightest windowsill.
  4. Change the water every 2 to 3 days so it stays clear. Cloudy water is the number one reason scraps rot instead of grow.
  5. Once you see new roots, move it to a small pot of soil for harvests that keep coming.
Tip: Water grows roots, soil grows food. Start in water so you can watch the roots form, then pot it up before the growth stalls.

The fastest win: green onions

Green onions (spring onions) are the perfect first regrow because you see results in a day.

  • Keep the white root ends about 3 cm long.
  • Stand them in a glass with a little water on a sunny sill.
  • New green tops start pushing up within 24 to 48 hours.

You can keep snipping the green tops for a couple of weeks in water. For months of harvests, pot them in soil once they take off.

Leafy bases: lettuce, celery, bok choy

Do not compost the base you cut off a romaine heart, a celery bunch, or a head of bok choy. Sit the base in a shallow dish with about a centimetre of water, cut side up, and small new leaves grow from the centre.

These give you a genuine “cut and come again” harvest for a few weeks. They will not regrow a whole new head, but you will get handfuls of fresh leaves before the base tires out. Move them to soil for the best results.

Herbs: mint, basil, cilantro and more

This is where scraps turn into real, lasting plants. Soft-stemmed herbs root from cuttings incredibly easily.

  • Take a stem about 10 cm long and strip the lower leaves.
  • Stand it in water on a windowsill, leaves above the surface.
  • Roots appear in about a week, then pot it up.

Mint and basil are the most beginner-proof of all. In fact, growing mint from a cutting is so reliable it is worth starting a couple at once. Cilantro (coriander) and parsley work the same way. Once rooted and potted, a single herb cutting can keep producing for months.

What does not really work (so you do not waste time)

A few viral “regrow” ideas look great in videos but rarely give you food worth eating:

  • Carrot, beet and radish tops regrow leafy greens, which are edible, but they never form a new root vegetable.
  • Onion, garlic and potato can grow into new plants if you plant them in soil, but they will not regenerate a new bulb in a glass of water.
  • Avocado pits can sprout a lovely houseplant, but fruit is years away and unlikely indoors.

None of these are wrong to try for fun. Just know they are novelties, not a food supply.

Watch out: If a scrap turns slimy or smells off, bin it and start fresh. Rot spreads fast in still water, so clean water every couple of days is the whole trick.

From scraps to a real windowsill garden

Regrowing scraps is the perfect confidence builder. Once you have watched roots appear in a glass, potting up a real plant feels easy. From there, fast growers like microgreens and basil are natural next steps. For the full picture, see our complete beginner’s guide to growing food at home.

Want help turning that first sprout into a plant that lasts? UrbanLeaf gives you one simple daily task for whatever you are growing, with weather-smart watering advice so beginners actually keep their plants alive. Free on iPhone. 🌱

Frequently asked questions

What vegetables regrow best from scraps?

Green onions, leafy bases like romaine lettuce, celery and bok choy, and herb cuttings like mint, basil and cilantro regrow the most reliably. Green onions are the fastest, often growing within a day or two.

How do you regrow green onions?

Keep the white root ends about 3 cm long, stand them root-down in a glass with a little water on a sunny windowsill, and change the water every 2 to 3 days. New green tops appear within 24 to 48 hours.

Can you regrow vegetables in just water?

You can start most scraps in water, but for lasting harvests move them to soil once they root. Water alone runs out of nutrients, so growth slows and flavour fades after a week or two.

Do potatoes, carrots and onions regrow from scraps?

Not into new whole vegetables. A carrot top regrows leafy greens (edible, but not a new carrot), and a sprouting potato can be planted to grow a new plant. For quick windowsill wins, stick to green onions, leafy bases and herbs.