Jerusalem artichoke (Helianthus tuberosus), also known as sunchoke, is not from Jerusalem and not an artichoke. Instead, it takes its first name from girasole, Italian for "turn toward the sun," which is something this plant and other sunflowers do from dawn to dusk. In late summer, beneath the 7-foot, bright yellow sunflowers lie rough, tuberous roots with a nutty flavor. They're tasty fresh or cooked like potatoes.
WHERE IT GROWS: All zones.
PLANTING, CARE: Plant tubers on the north side of the garden, where they won't shade shorter plants, or in a space you can contain (in the narrow strip between the sidewalk and garage, for example). Four to six weeks before the last spring frost, plant the tubers whole or in two-eyed chunks (eyes up) 5 inches deep. If you have to plant in open garden, surround the plants with the kind of plastic root barrier that's often sold to contain bamboo. If you don't, they'll spread and become pests.
HARVESTING: Start digging tubers for harvest after the first frost, which sweetens them. You can leave some tubers in the ground for winter harvest and for next year's plants, or dig all the tubers and refrigerate them. Any tuber you leave in the ground will regrow and spread.
Scrub or peel the tubers; submerge them in water with a little lemon juice added to prevent browning, then dice them to use like water chestnuts in salads or stir-fries. Or steam them until tender (about 15 minutes if whole, 5 to 10 minutes for slices) and season with butter, tarragon, or lemon juice.
BEST VARIETIES: For smooth tubers (easier to clean), try 'Red Fuseau', which doesn't bloom readily. For lots of rather rough tubers, try 'Stampede'.