Once they're established, growing Jerusalem artichokes is more a matter of containing than encouraging them. These productive, nutty-flavored tubers can stand in for potatoes.
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Potatoes aren’t the only terrific tuber out there. Native to central North America, Jerusalem artichokes (Helianthus tuberosus) — often called by the more modern name “sunchokes” — are so prolific they can become invasive, but if handled properly, they will be a productive and rewarding crop. The edible parts of these plants are their knobby roots, which have a crisp texture like that of water chestnuts. When cooked, they become a soft, nutty alternative to potatoes.
American and European gardeners have been selecting superior strains over the course of 300 years growing Jerusalem artichokes. A few of these are distinctive enough to bear variety names. Keep in mind that unnamed strains grown by local gardeners may be a great fit for your garden, so look for them at local farmers markets or plant swaps. You can also try growing from supermarket sunchokes, purchasing and planting them in early spring.
Strains vary by skin color, root shape, and maturation time. White-skinned strains include the early-maturing ‘Stampede’ variety, which develops crisp, round roots quickly enough to be grown in climates with short summers. The roots of slower-growing ‘Clearwater’ and ‘White Fuseau’ are longer, which makes them easier to scrub and peel.
Red-skinned strains include ‘Red Fuseau,’ which has red skin over topshaped roots with few attached round nodules, making the roots easy to clean. The roots of ‘Red Rover,’ ‘Waldspinel,’ and a few other red varieties are so long that these varieties are sometimes called “fingerling sunchokes.”
All of the varieties mentioned here are available from Oikos Tree Crops.
Plant small, whole tubers in early spring, or as late as you’d plant tomatoes. To get Jerusalem artichokes with big roots, give plants the longest growing season possible. After the first year, small tubers you missed while harvesting will usually shoot up sufficient plants to form a good crop.
A hardy, widely adapted perennial, Jerusalem artichokes grow best in well-drained soil with a near-neutral pH of about 7.0. Locate your crop in full sun but behind smaller vegetables, because the 10-foot-tall plants cast ample afternoon shade. A 5-by-5-foot bed (located outside the garden, where its perimeter can be easily mowed) is ideal for this exuberant crop. A 25-square-foot planting can produce more than 100 pounds of harvested tubers.
To prepare the site, dig out weeds and grasses, and dig in a 2-inch layer of compost to improve the soil’s structure. Plant small seed tubers 4 to 5 inches deep and 16 inches apart. When the plants are about a foot tall, mulch with grass clippings, rotting leaves, or another organic mulch that will help retain soil moisture.
Cool soil temperatures improve flavor and texture. If your winters are cold, begin digging Jerusalem artichokes in late fall, at least two weeks after your first hard freeze. In milder areas, wait until midwinter to dig your tubers.
Using a digging fork, start at one end of the bed and work your way across, feeling for tubers with your fingers. Tubers can sometimes be hiding a foot deep. Harvesting can continue through winter as long as the ground isn’t frozen. In very cold climates, digging will often have to wait until the soil thaws in spring.
Rinse and pat dry harvested tubers before storing them in a refrigerator or cool root cellar. Jerusalem artichokes will keep in the fridge for a couple of months.
When harvesting, set aside tubers smaller than a robin’s egg, or simply drop them back into the soil to replant the crop. To keep plants from becoming invasive, lop off their yellow blossoms and enjoy them as cut flowers. With their flowers removed, the plants will use their late-season energy to grow plump roots instead of producing seeds, and they won’t shed seeds all over your garden.
Water Well. If the weather is dry in early fall, give your Jerusalem artichokes deep drenchings to increase tuber size.
Pair With Pole Beans. Try planting a few pole beans on the sunny side of your Jerusalem artichokes. The beans will use the sturdy Jerusalem artichoke stems as a living trellis.
Don’t Sweat Pests and Diseases. Mysterious holes in leaves are usually the work of night-flying beetles or Japanese beetles. Jerusalem artichokes have no trouble tolerating light insect feeding, and the plants are seldom bothered by diseases.
You can cook Jerusalem artichokes peeled or unpeeled. Scrub them with a stiff brush just before you cook them. Sorting your tubers by size will simplify preparation.
Try cutting your largest tubers into matchsticks for slaw or grating them into not-really-potato pancakes. Fry sliced Jerusalem artichokes as you would potatoes, or bake slices in a low-temperature oven for a long period of time to make “potato” chips. Medium-sized Jerusalem artichokes that have numerous bumps and knobs can be boiled whole in their skins and then mashed and sieved to form the basis for Jerusalem artichoke soup, which many say is the best way to eat the veggie. Rather than struggling to peel small, knobby tubers, scrub them well and then roast them with a little olive oil and sea salt. After they’ve cooled, eat them as finger food by squeezing the soft middle into your mouth — a North American food practice that dates back more than 1,000 years.
Jerusalem artichokes get their sweetness from a unique sugar called inulin, which the body metabolizes much more slowly than it does other sugars. This makes the veggie a preferred food for diabetics, and for anyone who wants to avoid eating simple sugars and starches. Jerusalem artichokes are rich in iron, potassium and a range of B vitamins.
Contributing editor Barbara Pleasant gardens in southwest Virginia, where she grows vegetables, herbs, fruits, flowers and a few lucky chickens. Contact Barbara by visiting her website or finding her on Google+.