Garlic chives can be eaten from its tiny bulb to its stalks to its flowers. They can easily be dug up, divided, and moved as well. In severe cold (below teens) they will die back, but all mine, as well as my Italian chives, come back in late winter. Thus all my plants, both Italian chives and garlic chives, are perennials.
If you grow the hardneck garlic varieties, they will grow stems with heads. You can either cut those stems off early, channeling all the energy into the forming bulb, or let it form a "seed-head". When those heads mature, about the same time that you'll dig up the bulbs, they will be loaded with tiny bulblets. You can eat those bulblets or plant them in late summer. When planted they will grow small stems, similar to the garlic chive and you can use those tops in your culinary dishes. Alternately you can just let them grow. Those stems will die back in the winter and they will only produce a small bulb the following spring/summer but if you leave them in the ground for another full year, you'll be able to harvest a normal size bulb the following spring/summer.
The softneck and Creole garlic varieties don't form that seed-head.
