Fall is a time of food harvesting, and a few of our native plants have provided tasty nutrition for humans for hundreds if not thousands of years. One such plant is a member of the sunflower family, noted not for its sunflower seeds (of which it rarely produces any) but for its delicious roots. That plant is Helianthus tuberosus – the Jerusalem Artichoke.
Common Name: Jerusalem Artichoke
Scientific Name: Helianthus tuberosus
Family: Asteraceae (Aster Family)
Alternate Common Names: Canada Potato, Earth-apple, Girasole, Sunchoke, Sunflower Artichoke, Sunroot, Tuberous Sunflower
Plant description: Jerusalem Artichoke has upright, rigid stems that are light green to reddish brown in colour and are covered in stiff hairs. The stems are unbranched except for towards the top where the flowers are found. Shallowly toothed leaves occur in an opposite arrangement on the lower part of the plant and become alternate as they ascend the stem. They are up to 25cm long and 12cm wide, lance-shaped to ovate with a pointed tip, rounded base and rough texture on top. Leaves are borne on winged leaf stalks ranging from 2cm to 7.5cm long, becoming shorter as they ascend the stem. Stems terminate with flowers that measure up to 9cm wide and are characterized by 10-20 yellow ray florets (petals) surrounding a slightly darker center disk. At the base of each flower are 2-3 sets of overlapping bracts, each being 1.2cm long, hairy and pointed. Flowers become dry seed heads each containing flattened and slightly downy seeds.
In the Garden: Jerusalem Artichoke is a very robust sunflower, putting on a dramatic display of yellow blooms in early fall. The tall, rigid stems persist throughout the winter months to extend wildlife value and garden interest. Best suited to large gardens or naturalized areas where it can be allowed to spread.
Exposure: full sun to part shade
Soil Type: prefer loose, well-drained soil, but will tolerate poor soils.
Moisture: moist to dry, but do not plant in areas that are consistently wet, as wet soil will rot the tubers
Height: 300 cm
Spread: 100 cm
Bloom Period: Aug, Sep, Oct
Fragrant (Y/N): Y
Showy Fruit (Y/N): N
Cut Flower (Y/N): Y
Pests: powdery mildew
Natural Habitat: open areas and moist thickets, prairie remnants along railroads, moist meadows along rivers, woodland borders, and is mostly found in disturbed areas
Wildlife value: several native bees are attracted to the flowers and the seeds are an important source of food for many birds and small mammals; when growing near streams or ponds, H. tuberosa stems and leaves are used by beavers and muskrats for dam and den building
Butterfly Larva Host Plant For: Gorgone Checkerspot (Chlosyne gorgone), Silvery Checkerspot (Chlosyne nycteis), and Painted Lady (Vanessa cardui)
USDA Hardiness Zone: 3-9
Propagation: Although possible to grow from seed, it is rarely done because this plant is so easy to grow from tubers or pieces of tubers (also, seeds tend to have low viability). Place your tubers in the ground, root-down and stalk-up, around 12.5 cm deep, and cover with soil. The best time to plant is in the spring after the danger of deep freezing has passed, but these hardy plants can be planted just about any time the ground isn’t frozen.
Additional Info: Jerusalem artichoke has been grown commercially for use as a human food source, for livestock feed and for ethanol production. Cultivated varieties yield white tubers that are clustered near the main stem as opposed to wild types which produce reddish elongated tubers at the end of long rhizomes.
Jerusalem artichoke is a very aggressive spreader in the garden. In my own garden, I planted them in half of a plastic 45 gallon drum, buried in the ground, to prevent spreading into my lawn. Each fall I harvest all the pieces of root I can find, and the little pieces I miss are enough to provide a full crop the next year.
Jerusalem Artichoke on the menu: I normally don’t offer commentary on the edibility of native plants in the garden, nor instruction on preparing them as food. This is because I grow native plants for wildlife, not for my own consumption. Jerusalem artichoke is one of the exceptions.
The tubers of Jerusalem Artichoke are said to have a nutty flavour, somewhere between a potato and artichoke hearts (having never had artichoke hearts, I can’t verify this – but they do not taste anything like potatoes, in my mind). Depending on the variety and the growing conditions, the tubers may be small, thumb-sized or less, right up to the size of your fist.
Wash the tubers well, then pretty much anything you can do with potatoes you can do with these tubers: sliced and pan fried, steamed, boiled, microwaved, added to soups, roasted or even eaten raw to add a bit of crunch in salads. Google “Jerusalem artichoke recipes” and you’ll find lots. My personal preference is roasted in the oven or wrapped in tinfoil on the BBQ – this seems to concentrate the sugars and flavour.
According to the Food Revolution Network (https://foodrevolution.org/blog/jerusalem-artichokes/), “Jerusalem artichokes are also a good source of inulin and oligofructose, which are types of fiber that act as potent prebiotics, or food for probiotics, which are the good bacteria in your gut. Inulin is a soluble fiber that also works to balance your blood sugar.”
However, there is a downside for those with sensitive stomachs. The inulin and oligofructose can cause gas, bloating, and even abdominal pain and diarrhea in certain people. For this reason they are also known as “fartichokes”. Cooking them well can help reduce this effect, and some say that harvesting after a good frost also helps. As with consuming any wild plants, though, if you are at all concerned be sure to do some research first and approach with caution.
Most sources I’ve read indicate you can loosely wrap the tubers in a paper towel and store in the crisper drawer for up to two weeks. I either have an excellent crisper, or exceptional tubers: mine stayed crisp and delicious for more than 6 months left loosely bagged in an unsealed large freezer bag in the drawer.
Happy Native Plant Gardening.