"Q: Many years ago I read about Jerusalem artichokes and was intrigued by their versatility, so when I saw some on the clearance shelf of my local garden center a couple of years ago I snatched them. They met my expectations for a fast-growing screen and I loved their little sunflowers, an added bonus I didn't expect. Knowing they were tubers and not knowing how to cook them, I left them in the ground for the next year, this year. I now have a nice crop of plants and went out to dig the roots to see what they looked like. My question : how big are they supposed to be? When do I harvest? I want to try my hand at cooking them but my tubers are quite small, only about twice the size of a person's finger knuckle. Is this all the bigger they get or should I leave them in the ground longer or should I have fertilized them better?

Answer:

Is there a gardener who hasn't dreamed of a vegetable that needs to be planted only once, is immune to most pests and diseases, is attractive, nutritious, and tasty, and produces a bountiful yield year after year with little care? Does such a vegetable exist? It does, and it's called a Jerusalem artichoke, although the plant has nothing to do with Jerusalem, or, for that matter, with artichokes. Its other name, 'sunchoke', is more apt, since that plant is one of approximately ninety species of sunflowers that grow all over the world. By any name the homely little tuber produced by this hardy, graceful, golden-blossomed plant is loaded with virtues and nearly devoid of vices. The knobby tubers of Helianthus tuberosus have a taste and texture somewhat like an early potato. Sunchokes are sweeter and crunchier than potatoes, however, and they're as versatile in the kitchen as they are in the garden. Sunchokes are delicious eaten raw in salads or nibbled with a dip; like potatoes, they can be boiled and mashed, baked and French fried, even cooked in a casserole with a cheese sauce and topping. To stews they contribute a novel flavor, and their juice helps thicken and jell the liquid. They also make a tasty substitute for water chestnuts in stir-fry dishes. In cooking with sunchokes the most important thing to keep in mind is that they should not be put in an iron pot, or they will blacken.

Nutritionally sunchokes rate high. One of the tuber's greatest assets is its low caloric content : four small, freshly harvested sunchokes contain a mere 7 calories. If sunchokes are kept long in storage, their chemical make-up will change, and the same four sunchokes may contain as much as 75 calories, but that's still fewer than a medium-sized apple. The protein content of the sunchoke is surprisingly high for a vegetable � 2.3 grams in an average serving. It is also rich in minerals like iron, phosphorus, and calcium, and, as a bonus, contains small amounts of Vitamin A, thiamin, riboflavin, niacin, and Vitamin C. All that nutritional power, and the sunchoke contains only 2 per cent sugar. East of the Mississippi sunchokes are found growing wild along roadsides or in abandoned fields where they held on and spread long after homesteaders who planted the tubers disappeared. At first glance, sunchokes resemble ordinary sunflowers, but they are not difficult to identify, especially when the plants are in bloom. Sunchokes tend to be taller, more slender, and more graceful than common sunflowers, and although the blooms of the sunchoke are the same golden color, they lack the cultivated sunflower's large center mosaic of seeds and have smaller centers than wild sunflowers. The sunchoke's leaves are also slender and more pointed than leaves of other sunflowers.

The growing habits of sunchokes endear them to even the least industrious of gardeners. Put a few tubers in almost any kind of ground in spring or early fall, leave them undisturbed for a year, and forever after you will reap a rich harvest of food from September through March. If the sunchoke has a vice, it is persistence. Once established, the plants are difficult to get rid of, so you should plant them where you want them to remain. You can buy tubers for planting from the supermarket. Plant them in any kind of soil about 4 to 6 inches deep, spaced as far apart as you choose. The sunchokes will multiply so extensively that after a few years they'll blanket the entire area. After planting keep the bed watered if the weather is dry. By midsummer the plants will be 5 to 10 feet high, and in September blossoms will appear.

It's best not to dig the tubers the first year. In the second autumn, after the first killing frost, allow the stalks to dry out for a week or so to 'cure' the tubers, then cut off the stalks and get out your spade. From a row no more than 15 feet long, you can expect at least half a bushel and possibly two bushels of tubers. The prudent plan is to dig just enough tubers for a few weeks' meals. Sunchoke tubers can be dug at intervals throughout winter and as late as March when the tubers will begin to sprout new plants. Don't fear for next year's harvest; you won't get all the sunchokes even if you try, and those left behind will produce ample new plants. When digging or handling the tubers, a long- sleeved shirt is advised. The leaves and stems of sunchokes are hairy and can produce a prickly rash on sensitive skin.

For storage in the refrigerator, the sunchokes should be cleaned of dirt and placed in closed plastic bags to prevent moisture loss. Don't store them wet, for that will encourage rot. Sunchokes can be kept in plastic for as long as three months on a lower shelf of the refrigerator with no loss of crispness or flavor. To prepare sunchokes for cooking, peel, scrape, or scrub them with a stiff brush to remove the brown outer skin. Like the skin of a potato, it is nutritious, but the finished product is more attractive without the skin. Sunchoke skins peel off easily if the tubes are cooked in their jackets. Cooking time is about half that for potatoes. The tubers were brought to France in 1616 by the explorer Samuel de Champlain. The French called them poired de terre ('earth pears') or artichauts de Canada ('Canadian artichokes'). The plant soon spread rapidly all over Europe. Their resemblance to the taste of artichoke hearts would explain how the name 'artichoke' came to be attached to the tubers. The 'Jerusalem' part of the name appears to have come from Italy, where the plants were called girasole, a combination of the Latin girare ('to turn') and sol (the sun), because of their sunflower like habit of turning their blossoms to the sun. Perhaps girasole became garbled into Jerusalem, and the name stuck.

Sunchokes can be turned into pickles, served in an especially good soup with watercress, cooked in a Provencale sauce with tomatoes, turned into a savory dish with cheese, combined with shrimp in an uncommonly tasty salad with vinaigrette sauce, and given an Indian flavor with curry powder, chopped chutney, and golden raisins. What more could anyone ask from a single vegetable? It seems almost redundant to add that the Indians of North America drank a tea make from the leaves of the Jerusalem artichoke to relieve rheumatic pains and ate the heads of the plants as well. Any sunny corner can become a home for sunchokes. They'll provide nutritious food that is tasty, versatile, nonfattening, and best of all, a cinch to grow. 
Treat 'em like potatoes! An easy way to become familiar with this new/old vegetable, the sunchoke, is to treat it like a potato. Turn Sunchokes into delicious French fries by slicing peeled tubers into sticks, brushing them with oil and broiling them in a flat pan. Sunchokes make an agreeable variation of the standard potato salad, too. The late Euell Gibbons, author of 'Stalking the Wild Asparagus', suggested slicing them ray for a salad with watercress and thinly sliced leeks mixed with French dressing. Sliced and fried rank-style, or mixed half-and-half with sliced potatoes and a bit of onion, they make a tasty side dish for broiled meat. Made into a soup like the one below, they tempt the taste buds of the sniffling flu victim while providing superior, easily digested nourishment. 

SUNCHOKE SOUP
1 large onion, chopped 
1 clove garlic, minced 
3 tbsp. butter or margarine 
2 cups milk 
1 lb. sunchokes, scrubbed 
2 cups chopped watercress and diced small 
Dash of nutmeg 
Salt and pepper to taste 

In large saucepan, saute the onion and garlic in the butter until tender. Add milk, sunchokes, watercress, nutmeg, and salt and pepper, and simmer, covered, for about half an hour. Garnish with croutons and grated Parmesan cheese. Serves 4. 
Note : If you want a thicker soup, mix 1 tablespoon cornstarch or arrowroot with the milk before cooking. For a summer variation, omit the watercress, puree the soup in a blender, and serve chilled, garnished with snipped chives or parsley.

MARINATED SUNCHOKES AND GREEN BEANS
1-1/2 cups Sunchokes 
1 cup fresh green beans, scrubbed or peeled steamed until just crunchy, or canned beans cut in julienne strips 
1 cup sliced mushrooms 
1/4 cup sliced ripe olives 
1/4 cup olive oil
Juice of one lemon 
2 tbsp. chopped fresh parsley 
2 cloves garlic 
Salt and pepper to taste 

In a large bowl, mix the sunchokes, green beans, mushrooms, and olives. In a separate bowl whisk together the remaining ingredients, pour over vegetables, and mix gently. Refrigerate at least two hours, stirring once or twice. Serve on a bed of greens. Serves 4.

SUNCHOKES IN TOMATO SAUCE
4 tbsp. olive oil 
1 medium onion, chopped 
1 clove garlic, minced 
2-1/2 lbs. of sunchokes, scrubbed or peeled, and quartered 
3 large tomatoes, peeled and cut in small pieces 
Juice of lemon 
1 tsp. oregano leaves 
Salt and pepper to taste 
2 tbsp. chopped parsley 
2 tbsp. tomato paste 

In large saucepan heat the oil, add the onion and garlic, and saute until tender. Add the sunchokes and stir to coat with oil. Add the remaining ingredients with 1 cup water and simmer for about half an hour, or until the sunchokes are just tender and the sauce in thick. If necessary, add more water while cooking. Serves 6.

Variation : For main dish, saute 1 pound of ground beef or lamb with the onion and garlic. Serve over rice.

Christine