Meaning "little onions" in Italian, cipollinis are small in size but big in taste. They come in red and white varieties, both of which are deliciously sweet. When roasted whole, they will melt in your mouth.
When purchasing fresh onions, look for vibrant, sturdy green tops, avoiding any that are limp, discolored, or slimy. Because they contain a higher water content than storage varieties, they won't keep long, so store them in the refrigerator and use them within a few days.
For garlic to produce the cloves we all know and love, the flower buds, or scapes, must be removed in early spring. Snakelike in appearance, they are slightly spicy and have become a springtime delicacy.
Leeks are an elegant and delicately flavored cousin of the onion. While growing, they are mounded with soil to keep their stems white and tender. Wash them carefully since the soil often gets caught between the plant's many layers.
The tiniest member of the onion family, chives are easy to cultivate. Don't dig up the whole plant; treat it as a cut-and-come-again crop, snipping some of the greens and flowers -- both are edible -- when needed.