Scapes have a garlicky flavor but very mild. They can certainly be used in cooking and in salads. IF you plant them, they will grow, but the bulb will only be tiny the first year. Leave it in the ground for another year and the bulb becomes larger and usable. I don't know whether you could leave it in the ground another year and harvest a really nice-size bulb. I have never done that. Many people who grow garlic one year but not the next, but still have garlic come up, was due to the fact that the scapes "self-seeded".
There was one vendor selling those scapes along with his Chinese Pink garlic at our local Farmer's Market.
