Don't know where I picked up this hint, but I learned that even if they had next to no roots at all you could plant supermarket green onions and harvest them, leaf (blade?) by leaf for MONTHS. This has proven to be true and I'm wondering if I'll see these next spring. The skinnier blades are from chives. Whenever I need either for a recipe I just go outside and snip. They're a bit sloppy, but are planted in a secluded spot.