Garlic scapes are thin, curly stems that emerge from the garlic plant in late spring and will eventually produce a flower. The scapes are cut out of the plant allowing the energy to go into the bulb and not the flower.  
The scapes taste just like garlic and can be used in many ways. Chop the scape finely and add raw to potato and pasta salads or saute in olive oil. Scapes mixed with basil and/or parsley make a delicious pesto.  
Grilled garlic scapes and scallions are delicious in summer potato, pasta and other salads.  
Storing garlic scapes could not be easier. Trim the ends and place in a glass of water on your windowsill as you would cut flowers, changing the water every couple of days.