Pillar of the Community: Jerusalem Artichoke

Several Jerusalem artichokes have taken root in our little prairie garden. They’re sharing the space with false sunflowers and other prairie plants. Blooming in August and September, their yellow flowers with yellow centers are buzzing with a whole constellation of critters.

The story of the Jerusalem artichoke is that of an invasive that moved across the ocean from west to east. This plant is native to North America and for hundreds of years was planted and harvested by native Americans as a food crop. As early as 1617, settlers in the New World discovered the value of the Jerusalem artichoke and shipped samples of it back to Europe where it now flourishes as an invasive.

This native plant has nothing to do with Jerusalem or with artichokes. Ironically, the Jerusalem part of its name is actually a corruption of the Italian name for it, girasole, which means turning to the sun. The artichoke part of its name refers to the edible tubers the plant produces that reminded somebody of artichokes. They’re not related though. Its scientific name Helianthus tuberosus is more relevant to the plant itself. The first part comes from the Greek helios meaning sun and Anthos, meaning flower. The species name is from Latin meaning tuber. The plant goes by several other names as well, including earth apple, sunroot,  and sunchoke.

A member of the sunflower family, the Jerusalem artichoke grows up to ten feet tall on sturdy, rough and hairy stems that branch occasionally. At the ends of the branches near the top of the plant, 2- to 3-inch-wide solitary yellow flowers bloom in August and September. It has long, two-inch-wide, sandpapery rough leaves, and it spreads aggressively through its root system. Unchecked, it can form dense colonies and crowd out other plants.

The Jerusalem artichoke produces underground tubers which for centuries served as food for native Americans. A single plant can produce 70 or more of these tubers which look a bit like a cross between a potato and a ginger root and can be two to three inches across. Like potatoes and similar root vegetables, the tubers of the Jerusalem artichoke can be cut up and planted to produce new plants. Even small bits of the tubers can grow. Also like potatoes, the tubers provide a nutritious food. They are said to taste something like a water chestnut. Unlike a potato with its starchy insides, these tubers contain a carbohydrate called inulin that metabolizes into a form of natural sugar that doesn’t require insulin to break down. They can be eaten raw, boiled or roasted.

The tubers have been used for other purposes besides as food. In France and Germany, for some time they were used to ferment alcohol. They have been studied for use as biofuels and for their chemistry in recent years. Under cultivation, 2.5 acres can yield 70 tons of tubers.

Like most other native plants, the Jerusalem artichoke and its sunflower cousins have co-evolved with several native insect species. For example, the banded sunflower moth, a tiny moth with a dark band across its yellow-tan forewings lays its eggs on the leaves, positioning its larvae with a ready food supply when they hatch. Other native cohabitants include sunflower beetles, sunflower bud moths, sunflower moth, sunflower seed maggot, and  sunflower stem weevil. Other types of more generalist beetles and flies  snack on the leaves and stems as well. Deer and cattle will munch on the leaves if they’re hungry enough. Visitors including bees, flies, wasps, butterflies and moths exchange pollination services for nectar and pollen food. The Jerusalem artichoke is not unique in standing as a host for so many small creatures, but it does represent the complex and varied roles that one plant can play in an ecosystem.

After the first hard frost, we plan to dig up some of the tubers and see how they are for food. This will also help to thin the stand in the prairie garden so they don’t take it over.

Here’s the haul from digging up 2, second-year plants in November. About a dozen cigarette-size tubers. The plant is perennial; we assume the harvest will be bigger next year. Photo by Author.

Feature photo by Author. Alt text: A stand of Jerusalem Artichokes blooms in August. 4- to 6-ft-tall stalks, bristling with rough hairs and alternating leaves. A 3-inch blossom with yellow radiating petals tops each stalk. Plants were seeded two years ago when we established a prairie garden.