Too often we find that scallions go limp after just a few days in the fridge.
To prolong their shelf life, we tried several different storage methods, from wrapping them in moistened paper towels placed inside an open zipper-lock bag to tossing them naked into the crisper drawer. We found that standing the scallions in an inch of water in a tall container covered loosely with a zipper-lock bag worked best. Stored this way (with the water refreshed every three days), our scallions lasted for well over a week with very little loss in quality. (We’ve also used this trick to rejuvenate limp celery and broccoli. Standing their root ends in water can restore moisture and firm texture.)