Helianthus tuberosus

A fast-growing perennial reaching 2.4 m (7ft) tall and 0.6 m (2ft) wide, hardy to UK zone 4 and frost-hardy. Flowers in October with seeds ripening in November. Hermaphroditic flowers pollinated by bees and flies. Tolerates light sandy, medium loamy, or heavy clay soils; grows in nutritionally poor soil with good drainage. Tolerates mildly acid to mildly alkaline pH. Requires full sun, adapts to dry or moist conditions, and tolerates strong winds but not coastal exposure.

Description

An upright perennial plant up to 1-2 m high and a spread of 1 m. The stem is erect and unbranched. The leaves are dull green and sword shaped. The flowers are yellow and daisy like. It produces fleshy underground stem tubers of irregular shape. The skin of these tubers is very thin and often coloured yellow or red. The flesh is white. Tubers can be 10 cm long and 6 cm wide. There are several cultivated varieties.

Edible Uses

The tubers can be eaten raw or cooked and develop a pleasant sweetness over winter, particularly after frosts, making them reasonably acceptable raw at that stage. Otherwise they are generally best cooked and can be used in all the ways potatoes are used. The tubers are rich in inulin, a starch the body cannot digest, so they provide bulk without many calories. Some people tolerate inulin poorly — it can ferment in the gut and cause quite severe wind. Tubers can grow up to 10cm long and 6cm in diameter. They bruise easily and lose moisture rapidly, so are best left in the ground and harvested as needed. The inulin can be converted into fructose, a sweetener safe for diabetics. Roasted tubers also serve as a coffee substitute.

Traditional Uses

The tubers are eaten boiled or baked. They can be steamed, fried, pickled, pureed, or used in soups and casseroles. They can be eaten raw in salads. (They are suitable for people with diabetes) Roasted tubers are used as a coffee substitute.

Medicinal Uses

Jerusalem artichoke is reported to be aperient, aphrodisiac, cholagogue, diuretic, spermatogenetic, stomachic, and tonic. It is a folk remedy for diabetes and rheumatism.

Distribution

A temperate plant. Plants grow best when the temperature is 18°-26°C and frost free. They do best between 300 and 750 m altitude in the tropics. It needs light to medium well drained soils. Plants should be grown in an open sunny position. It is drought and frost resistant. It suits hardiness zones 7-9. In Sichuan.

Where It Grows

Africa, Albania, Argentina, Armenia, Asia, Australia, Balkans, Bosnia, Britain, Bulgaria, Burundi, Canada, Caucasus, Chile, China, Croatia, Cuba, Egypt, Europe, Fiji, France, Georgia, Germany, Hungary, India, Indochina, Iraq, Italy, Japan, Korea, Laos, Latvia, Libya, Luxembourg, Macedonia, Malaysia, Mediterranean, Middle East, Myanmar, Netherlands, New Zealand, Niue, North Africa, North America, Pacific, Papua New Guinea, PNG, Philippines, Romania, SE Asia, Serbia, Sicily, Slovenia, South Africa, Southern Africa, South America, Spain, Switzerland, Tasmania, Turkey, Türkiye, Uruguay, USA*, West Indies,

Cultivation

A very easily grown plant, it grows best in a loose circumneutral loam but succeeds in most soils and conditions in a sunny position. Plants are more productive when grown in a rich soil. Heavy soils produce the highest yields, but the tubers are easily damaged at harvest-time so lighter well-drained sandy loams are more suitable. Dislikes shade. Likes some lime in the soil. Jerusalem artichoke is reported to tolerate an annual precipitation of 31 to 282cm, an average annual temperature of 6.3 to 26.6°C and a pH in the range of 4.5 to 8.2. Jerusalem artichokes were cultivated as a food plant by the N. American Indians and they are today often grown in temperate areas for their edible tubers. There are some named varieties. The plant is a suitable crop in any soil and climate where corn (Zea mays) will grow. It survives in poor soil and in areas as cold as Alaska. It also tolerates hot to sub-zero temperatures. The first frost kills the stems and leaves, but the tubers can withstand freezing for months. The plants are particularly suited to dry regions and poor soils where they will out-yield potatoes. Tuber production occurs in response to decreasing day-length in late summer. Yields range from 1 - 2kg per square metre. The tubers are very cold-tolerant and can be safely left in the ground in the winter to be harvested as required. They can be attacked by slugs, however, and in sites prone to slug damage it is probably best to harvest the tubers in late autumn and store them over the winter. It is almost impossible to find all the tubers at harvest time, any left in the soil will grow away vigorously in the spring. Plants do not flower in northern Europe. They are sensitive to day-length hours, requiring longer periods of light from seedling to maturation of plant, and shorter periods for tuber formation. They do not grow where day-lengths vary little. The plant is good weed eradicator, it makes so dense a shade that few other plants can compete. The young growth is extremely attractive to slugs, plants can be totally destroyed by them. Members of this genus are rarely if ever troubled by browsing deer or rabbits. Plants only produce flowers in Britain after a long hot summer and seed is rarely formed. Grows well with corn. Plants can be invasive.

Propagation

Sow seed in spring in a cold frame. When seedlings are large enough to handle, prick them out into individual pots and grow on in the greenhouse through their first winter, then plant out in late spring or early summer after the last expected frosts. Propagation is most commonly done by tubers: harvest in late autumn or winter and either replant immediately or store in a cool but frost-free place and plant out in early spring. Tubers should be planted as early as possible once the soil can be worked, as late planting seriously reduces yield and tuber size. Plant whole tubers or pieces of about 50g, covered to a depth of 10cm. Pieces larger than 50g do not increase yield, while pieces smaller than 50g will reduce it. Planting too deep can delay emergence, weaken sprouts, and cause tubers to develop deeper, making harvest more difficult. For basal cuttings in spring, harvest shoots when about 10–15cm long with plenty of underground stem, pot into individual pots, and keep in light shade in a cold frame or greenhouse until rooting well before planting out in summer.

Other Uses

The plants are a good source of biomass, and the tubers are used industrially to produce alcohol; the alcohol fermented from the tubers is said to be of better quality than that from sugar beets. Jerusalem artichokes can be grown as a temporary summer screen, though they are a very temporary solution — they do not reach a reasonable height until July and begin dying down by October.

Production

Harvesting can start after 3 months.

Other Information

It is a commercially cultivated vegetable. Not commonly seen in Papua New Guinea.

Notes

Tubers contain inulin which can cause stomach wind in some people but is also tolerated by diabetics. Almost all Helianthus (60 species) in N and S America are edible.

Nutrition

Synonyms

Also Known As

Aardpeer, Aguaturma, Brahmokha, Cicoka, Cotufa, Csicsoka, Gerasole, Getnakhendzor, Girasole, Girsole, Gulia, Hartichuk, Hathipich, Hatichuk, Ju yu, Kiku-imo, Krtolest sonchogled, Laška repa, Nyameres, Pataca, Patatas de cana, Pe-po-di, Ramons, Sari khendzor, Say erd, Setembres, Sevibanaghd, Sevik, Sunchoke, Topinambo, Topinambour, Totrepa, Yabani yerelmasi, Yer elmasi, Zemjeno jabolko, Zemna yabalka

References (79)

• Altschul, S.V.R., 1973, Drugs and Foods from Little-known Plants. Notes in Harvard University Herbaria. Harvard Univ. Press. Massachusetts. no. 4828
• Ambasta, S.P. (Ed.), 2000, The Useful Plants of India. CSIR India. p 260
• Ari, S., et al, 2015, Ethnobotanical survey of plants used in Afyonkarahisar-Turkey. Journal of Ethnobiology and Ethnomedicine 11:84
• Beckstrom-Sternberg, Stephen M., and James A. Duke. "The Foodplant Database." http://probe.nalusda.gov:8300/cgi-bin/browse/foodplantdb.(ACEDB version 4.0 - data version July 1994)
• Bianchini, F., Corbetta, F., and Pistoia, M., 1975, Fruits of the Earth. Cassell. p 226

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