How do I select and store leeks?

Leeks are in the onion family (genus) but are not the same species as the bulb onion although they look very much like fatter green onions (scallions).  When selecting leeks in the store, look for ones that are not packaged because plastic packaging promotes rot.  They’re usually sold about 4 to a bunch. Select ones that have a slender bulb and tightly rolled dark green tops.

Leeks should be refrigerated.  The odor of leeks can be absorbed by other items in your fridge, so, when you get them home, wrap them LOOSELY in plastic to contain the odor and moisture. Then place them in your vegetable bin.  You can freeze them, but they may be mushy and bitter when defrosted.

Source(s):

About.com  Home Cooking   “Leek Selection and Storage”

http://homecooking.about.com/od/foodstorage/a/leekstorage.htm