Walking onions, so called because they have these little bulbils on top of the leaves and when they fall down, the bulbils send down roots and the plant "walks". Any way, the thing to do with these is when you get a whole bunch of these little bulbils on top, just clip them all and then separate them and go plant them in a row. Push in an onion about every 2 inches in the row. When these come up and grow you will have loads of fresh green onions. Enjoy! Oh ya, they are winter hardy. Keep a parent clump where it can stay the winter. Yes plant it now.
Gardening at 5000 feet elevation, zone 4/5 Northern Utah, Frost free from May 25 to September 8 +/- Plant a Garden