The high heat of the fire brings out the natural sugars in vegetables so they actually retain more of their flavor, vitamins and minerals than they do when cooked in water. From asparagus to corn, radicchio to sweet potatoes, vegetables are right at home over a bed of hot coals.
Shopping for Vegetables
In-season vegetables grown close to home are best. Look for vegetables that are plump, moist, and unwrinkled. Follow these guidelines when buying produce.
Asparagus Medium-sized and fat stalks grill better than very thin spears, which can be bitter. Peeling the bottom third of the spears with a vegetable peeler will help them cook evenly.
Season: February through June.
Bitter Greens Select heads of Belgian endive and radicchio that are firm, fat and crisp, with tight, unblemished leaves.
Season: year-round; best in winter.
Carrots, Parsnips and Turnips Choose smooth, firm vegetables that are free of cracks. Look for good color and a sweet smell. Small, mature vegetables have the best flavor.
Season: year-round; best in winter.
Corn Look for firm ears with plump kernels and a lot of creamy colored silk; avoid ears with heavily soiled or slimy fringe. The husks should be bright green and appear moist, not dried out.
Season: May through September.
Eggplants Look for evenly colored eggplants with shiny skin. Cut globe eggplants into slices for the grill; cook Asian eggplants whole or halved.
Season: year-round; peak in late summer.
Fennel Choose fresh bulbs that are smooth and tightly layered with no cracks or bruises. White and pale green, rounded bulbs tend to be more succulent than yellow or thin ones. Grocers sometimes incorrectly label fennel as sweet anise.
Season: year-round; peak from late fall through winter.
Mushrooms Look for mushrooms with relatively clean, firm caps. For portobellos, choose those that are evenly sized and have gills that appear clean, dry and distinct.
Season: year-round; best in late summer and early fall.
Onions Look for onions that are firm with smooth, dry skins. Avoid any with soft spots, particularly at the stem end; green shoots; moldy areas; or moist, wrinkled skins. In the spring, seek out sweet onions such as Maui, Vidalia or Walla Walla.
Season: year-round; sweet varieties in spring and late summer.
Peppers Look for peppers and chilies with smooth skin, as they will be easier to char on the grill than gnarled or grooved peppers. Thin-skinned varieties need a gentler touch so that they don't develop holes while grilling from too-high heat.
Season: year-round; best late summer through fall.
Potatoes and Sweet Potatoes Look for firm, unblemished tubers that are not wrinkled, tinged with green or cracked. Avoid potatoes that have sprouted buds.
Season: year-round; new potatoes best in spring; sweet potatoes best in fall and winter.
Summer Squashes Select zucchini, yellow crooknecks, pattypans and other summer squashes that are mature enough to have full flavor yet small enough to be tender and free of large seeds.
Season: year-round; best June through September.
Tomatoes Select tomatoes only in season, and make sure they are firm but ripe. Heirloom varieties are particularly flavorful. Never store tomatoes in the refrigerator or they will become mealy. A sunny windowsill is a good place to store underripe tomatoes.
Season: June through September.
Winter Squashes Look for firm, unblemished squashes that feel heavy for their size.
Season: some varieties available year-round; widest selection in fall and winter.
Preparing Vegetables for Grilling
Prevent vegetables from sticking to the rack by coat both the rack and the vegetables with oil before grilling. A grilling basket or grill screen is handy for cooking small vegetables that may fall through the spaces in the rack.
Testing Vegetables for Doneness
Piercing a vegetable with a skewer or the tip of a knife will give you some idea of whether or not they are done. However, the best way to test a vegetable for doneness it to cut off a piece and eat it. Some vegetables, such as asparagus and fennel, are most satisfying when tender-crisp, which means tender when you first bite into them and crunchy at the center. Other vegetables, such as eggplants and mushrooms, should be cooked until soft throughout.