Here's The Best Way To Store Green Onions
Whether you're topping a bowl of slurpy ramen or making a savory burger sauce, green onions (also known as scallions, but quite different from chives) provide just the right hit of light allium-y goodness. The best thing is that they're cheap and plentiful at most supermarkets, but they have a tendency to go slimy and brown fairly soon if not properly stored.
The way to store green onions so that they don't become mush within a few days is to first remove the rubber bands they so often come bound in and peel off any leaves that are already bruised or starting to turn (if there are any stalks that are entirely beyond redemption, just toss them in the garbage, too). Lay down a full paper towel sheet on a flat surface and spread out the green onions over top of it so that the white parts, at least, aren't touching.
Lay another full paper towel down on top of the green onions and then loosely roll them up (they don't have to be in a super-tight bundle, just enough so that the onions don't fall out). Place in a plastic bag, pushing as much air out as you can, and keep in your veggie drawer. The plastic bag keeps the dry fridge air out, while the paper towels absorb excess moisture.
Extending green onions' shelf-life even further
If you're making a meal that calls for just the green part of the scallions, you can actually save the white scraps to grow more. That's right — green onions are regenerative, and if you place the whites, with their roots still attached, into a glass of water and put them in a sunny window, the leaves will start to re-form. You do have to change the water every few days, but once enough green has grown back, you can snip them off as needed.
You can also freeze your green onions for later use; just give them a rinse, let them dry fully, and then place them in a freezer-safe sealable bag before popping them in the freezer. You can also pre-cut them into little pieces for sprinkling before freezing, too. Because they do tend to lose their crispness during the freeze/thaw process, they are best used to add flavor in dishes, like the vegetarian soup ajo blanco.