I'd never heard of a garlic scape until a few years ago when I belonged to a CSA and these strange "vegetables" appeared in my weekly box. They were garlic scapes, which are the flower stalks made this time of year by hardneck garlic. You really don't want your garlic to put energy into flowering, so the scapes should be cut off just as they start to curl, which for my garlic, is now! Don't throw them away though! Scapes are a wonderful preview of garlic yet-to-come. You can puree them with olive oil and pine nuts to make a great pesto. Or puree them with white cannellini beans to make a terrific bean dip. Or cut them into pieces and stir fry them with the veggies of your choice. Or just use them as you would regular garlic. The scapes have a milder, less pungent garlic flavor.
Don't have your own garlic scapes but want to try them? Visit your local farmers' market. If you have garlic-growers at your market they'll most likely be selling their scapes about now! Look for ones that aren't too tightly curled: they're more tender than older, more mature scapes. I liked scapes so much that all the garlic bulbs I plant are hardneck garlic so that I can harvest a crop of scapes every year!