The wonderful cartoonist B. Kliban titled one of his books “Never Eat Anything Bigger Than Your Head,” a piece of advice I’ve had little trouble following, unless you count the odd watermelon or heirloom pumpkin. Certainly I’d never thought to tuck into a giant kohlrabi.

A kohlrabi is a strange-looking object even when it’s not the size of a soccer ball — a green or purple globe that sits just at soil level, with leaf stems protruding upward at various longitudes and latitudes on its surface. The more typical varieties I’ve chosen to grow, such as Kolibri, are harvested at baseball size or smaller — crisp and tender enough to eat raw. They do best in the cool weather of fall, because summer’s heat makes them pithy. Their leaves, when young, are no less edible than that of any brassica such as cabbage, turnip or kale.

On our farm we also plant a variety of giant kohlrabi called Kossack, available from a number of seed catalogues. It’s relegated to the area where we grow storage crops to feed to the livestock. Because it looks no more appetizing than the red and yellow mangelwurzels (fodder beets) in the next field, it never occurred to any of us to eat it. Then one day some of our crew started cooking with it, and suddenly it’s our new foodie sensation.

Draw your sword, slice into a six-pound giant kohlrabi and — amazingly — you’ll find flesh as tender and crisp as that of a baby radish in spring. If you harvest it in late fall or early winter after some frosts, it’s nearly as sweet as a parsnip, and with a more gentle flavor. In fact, of all the brassica roots, this is the mildest, so much so that dairy farmers traditionally fed it to their cows as a winter succulent because it didn’t make their milk taste like turnips and rutabagas.

Fall is the best time to coax anyone, from the old and stodgy to the young and picky, to try a new brassica, because of the sweet taste the season brings. So we’ve started to offer these intimidating roots at the farmer’s market. We cut one open for folks to sample, and they buy them eagerly. I’ve set about finding the best ways to cook them, including creamy purees and root vegetable medleys. Cooked as french fries, in grapeseed oil, they lose much of their crispness but are still delicious, simply sprinkled with salt and pepper. I like them even better when sliced into pancakes, fried briefly in olive oil, then finished under a hot broiler, topped with breadcrumbs or parmesan cheese. I’d like to experiment some more, maybe pickling thin strips briefly in brine, then draining and seasoning them with vinegar, mustard seeds, garlic and a pinch of sugar the way my neighbor Mia does. I have all winter to try; our mound of these roots is taller than I am, with a few that are, yes, bigger than my head.

Giant kohlrabi (Barbara Damrosch)

There’s a lesson to be learned here about the rewards of curiosity when it comes to vegetables, which should not always be judged by their looks. Now about those mangelwurzels . . .

Damrosch's new book ,"The Four Season Farm Gardener's Cookbook," will arrive in March.

Tip of the week

Poinsettias should be watered when the soil feels dry to the touch. Take the pot to the sink and water the soil, not the leaves, with lukewarm water. Allow the pot to drain for a few minutes before returning it to its saucer. Keep poinsettias away from drafts and heat registers. They prefer cool, bright rooms but can be placed in darker locations for a few hours as festivities require.

— Adrian Higgins