How long do green onions last in the fridge?

The short version: a bunch of green onions (scallions, spring onions) wrapped loosely dry and kept in the crisper drawer is good for roughly a week to ten days before the tops go limp and yellow. The same bunch trimmed at the root, stood upright in a jar with an inch or two of water and left in the fridge, can stay usable for two to three weeks — and will often push out a little new growth from the centre while it sits there. That is a real difference, not a folk remedy, and it comes down to where a green onion actually loses moisture from, which a sealed bag does nothing to address.

Why the green tops wilt before the white end does

A green onion's leaves are not solid the way a chive or a blade of grass looks like it should be — cut one crosswise and it is a hollow tube, open at the top where it was trimmed or where it was cut from the plant. That open end is a direct route for moisture to leave the leaf, and it is also why the tips are usually the first part of the bunch to go limp: they are furthest from the base and have the most exposed cut surface relative to how much water they hold. The white root end is a different piece of plant entirely — denser, with far less surface area exposed to the air, and still structurally capable of drawing up water through the root if it is given any. Wrapping the whole bunch in a bag slows evaporation everywhere at once, which is better than nothing, but it does not change the fact that the leaves are losing water they can never get back. It just stretches out a one-way process.

Two storage methods that are not doing the same job

Wrapped dry in a paper towel and then a loosely closed bag in the crisper drawer, green onions hold their crunch for about a week before the tops start to soften and dull. That method works by cutting down airflow around the leaves, so less water escapes into the fridge's dry air — but it is purely defensive, slowing a loss it cannot reverse. Standing the bunch root-down in a jar with a shallow pool of water changes the equation rather than just slowing it: the cut root can still take up water the way it did in the ground, replacing at least some of what the leaves are losing rather than only rationing it. That is the entire reason the water method reliably outlasts the bag by a week or more, and why it is worth the minor hassle of a jar taking up a shelf. The water is worth changing every couple of days — not for the onions' sake so much as because standing water left too long can grow its own cloudy film, which is easy to rinse away and not worth ignoring.

Regrowth is real, but it is not the same as the bunch staying fresh

Leaving a trimmed root end in water on a windowsill and watching new green push up from the centre is a genuine, well-known trick, not something specific to how this bunch happens to be stored — and it will keep happening for a jar sitting in the fridge too, just more slowly in the cold. It is worth knowing what it is and is not, though. The new growth is thinner and milder than the original leaves, and it is coming at the expense of whatever the root has stored, which is finite. A root end usually manages one or two rounds of meaningful new growth before it has nothing left to push out, at which point the base itself softens and is done. Regrowth is a genuine bonus from a method you were already using to keep the rest of the bunch usable longer, not a reason to expect a jar of green onions to renew itself indefinitely.

Reading a bunch of green onions honestly

• Limp, floppy leaves with yellowing or browning tips. This is ordinary moisture loss, exactly as described above, and it is not a reason to throw the bunch out. Trim the worst of it and use the rest, especially in anything cooked, where crispness was never doing much work anyway.
• Leaves that have gone properly slimy or mushy to the touch, not just soft. That is decay rather than dehydration, and it is usually accompanied by a sour or off smell. That part is done.
• The white base turning soft, brown, or slick rather than firm and pale. The root end is where rot actually sets in when it happens, and once it does, the whole bunch is on its way out even if the green tops still look fine.
• A cloudy or filmy jar of standing water. On its own this is not a sign the onions are bad — it is the water that needs changing, not necessarily the onions that need discarding, unless the smell coming off them has changed too.

A bunch of green onions is also an easy thing to lose entirely, because it rarely gets its own space in the fridge — it ends up tucked behind whatever was put in front of it, or wrapped in a bag that looks identical to three other bags of vegetables. Munch logs each item against the day it came home and shows what needs using first across everyone in the household, so a bunch bought a week and a half ago for one recipe does not sit forgotten behind Tuesday's shopping until the tops have already gone.

None of this needs a different rule for every day a bunch sits in the fridge. It needs one distinction: the green tops and the white base are not ageing at the same rate or for the same reason, and a storage method that actually replaces lost water at the root — rather than just slowing the loss in the leaves — is why standing green onions in a jar consistently beats wrapping them in a bag.