Root vegetables are pretty much what they sound like: vegetables that grow in the earth and must be dug up to be harvested. Since they grow underground, they absorb a lot of nutrients from the soil, and so are nutritional powerhouses, usually also high in starch.

Root vegetables include potatoes, yams and carrots, as well as beets, parsnips, turnips, rutabagas, yuca, kohlrabi, the onion family, garlic, celery root (or celeriac), turmeric, jicama, radishes (including daikon and horseradish) and ginger.

Some root vegetables imported from temperate climates get sweeter once the first frost hits. The cold causes the roots to work hard to prevent the plants from freezing, which causes the natural starches to convert to sugar. Carrots, turnips, rutabagas and beets are good examples.

This makes winter the perfect time to explore the world of root vegetables. There is beauty to cooking with the season, not just because it feels in sync with the planet, but also because it compels you to make the most of what is available, whether those ingredients are familiar … or not so much.

Robert Schueller, head of marketing at Melissa’s Produce, a specialty produce company based in California, says specific root vegetables are having a moment. In the world of potatoes, for instance, baby potatoes are especially popular, including Dutch yellow, ruby gold, red, mixed fingerlings and gemstone.

He calls parsnips “the new carrot.” Related to both carrots and parsley, they look much like large, pale carrots with a fatter base. The flavor, when cooked, is like a sweeter carrot, and parsnips can be used in pretty much any recipe that calls for carrots, when you want heightened sweetness. Parsnips are common in traditional Jewish chicken noodle soup. They also can be mashed with potatoes or on their own, as well as roasted.

Kohlrabi has also become trendy, Schueller says. Each looks a bit like a UFO with a bunch of stems sticking out willy nilly, in shades of pale green to purplish, with a pale interior. Kohlrabi can be eaten cooked or raw; raw, its flavor and texture are reminiscent of peeled broccoli stems, with a bit of peppery radish thrown in.

Radishes are popular not just for their spicy flavor but for the visual pop they give to salads and other dishes. The watermelon radish continues to trend, Schueller says, for its dramatic look: green on the outside, hot pink on the inside.

And multicolored carrots are gaining traction because of how beautiful they look on a plate, in hues of purple, red, orange and yellow. They can be used just as regular orange carrots are; try them cut lengthwise and simply roasted with olive oil and salt, perhaps served with a tapenade or pesto vinaigrette.

Celery root, horseradish, sweet potatoes and shallots are other root vegetables Scheuller sees gaining in popularity because of their use by restaurant chefs.

STORAGE

In general, keep in a cool, dark place with ventilation.

>> Carrots, celeriac, parsnips, turnips and radishes do well in the fridge crisper drawer.

>> Store onions separately, as they emit gases that accelerate the spoiling of other vegetables, especially potatoes.

>> Remove green tops before storing roots. Wrap the greens in a damp paper towel and refrigerate; use them as you would use any cooking greens, like kale or spinach.

SELECTION

>> Choose root vegetables that are fim and heavy for their size, with no soft spots.

>> Skins should be free of blemishes; green tops should not be wilted.

COOKING

>> The tough outer skin of most root vegetables should be removed; they sometimes have a waxy coating that slows spoilage. Use a vegetable peeler or a sharp paring knife.

>> Others, such as carrots and Jerusalem artichokes, may just need a good scrub to remove dirt and any unwanted bits and bobs from the skin.

>> Most are best diced, sliced or cubed before cooking, to speed things up and, in the case of roasting, to get those nice caramelized surfaces.

>> Add to soups, stews and casseroles. For casseroles, you might want to cook them at least partially first, since they may take a little longer to become tender than the other ingredients.