Thursday, 3 August 2017


“What has Athens to do with Jerusalem?” - Tertullian 

The Jerusalem artichoke (Helianthus tuberosus), also called sunroot, sunchoke, earth apple or topinambour, is a species of sunflower native to eastern North America, and found from eastern Canada and Maine west to North Dakota, and south to northern Florida and Texas. It is also cultivated widely across the temperate zone for its tuber, which is used as a root vegetable.

Despite its name, the Jerusalem artichoke has no relation to Jerusalem, and it is not a type of artichoke, though the two are distantly related as members of the daisy family. The origin of the “Jerusalem” part of the name is uncertain. Italian settlers in the United States called the plant girasole, the Italian word for sunflower, because of its resemblance to the garden sunflower (both plants are members of the genus Helianthus). Over time, the name girasole may have been changed to Jerusalem. The taste of the tuber is said to resemble artichokes. 

Helianthus tuberosus is a herbaceous perennial plant growing to 1.5–3 m tall with opposite leaves on the upper part of the stem but alternate below. The leaves have a rough, hairy texture. Larger leaves on the lower stem are broad ovoid-acute and can be up to 30 cm long. Leaves higher on the stem are smaller and narrower. The flowers are yellow and produced in capitate flowerheads, which are 5–10 cm in diameter, with 10–20 ray florets and 60 or more small disc florets. The tubers are elongated and uneven, typically 7.5–10 cm long and 3–5 cm thick, and vaguely resembling ginger root in appearance, with a crisp texture when raw. They vary in colour from pale brown to white, red, or purple.

Before the arrival of Europeans, Native Americans cultivated Helianthus tuberosus as a food source. The tubers persist for years after being planted, so that the species expanded its range from central North America to the eastern and western regions. Early European colonists learned of this, and sent tubers back to Europe, where the plant became a popular crop and naturalised there. It later gradually fell into obscurity in North America, but attempts to market it commercially have been successful in the late 1900s and early 2000s.

The tuber contains about 2% protein, no oil, and a surprising lack of starch. It is rich in the carbohydrate inulin (76%), which is a polymer of the monosaccharide fructose. Tubers stored for any length of time will convert their inulin into its component fructose. Jerusalem artichokes have an underlying sweet taste because of the fructose, which is about one and a half times as sweet as sucrose. It has also been reported as a folk remedy for diabetes.

Temperature variances have been shown to affect the amount of inulin the Jerusalem artichoke can produce. When not in tropical regions, it has been shown to make less inulin than when it is in a warmer region. Cultivate from tubers or tuber fragments in early Spring, or leave tubers and/or their fragments in the ground after harvesting, which can be done as required with a garden fork from late Autumn into Winter. The plant is persistent; if they are not required the following year, ensure that every last tuber and/or fragment is removed. We have only planted them once in our garden and they come back year after year, even after extensive and thorough harvesting.

The tubers are sometimes used as a substitute for potatoes: They have a similar consistency, and in their raw form have a similar texture, but a sweeter, nuttier flavour. Raw and sliced thinly, they are fit for a salad. Their inulin form of carbohydrates give the tubers a tendency to become soft and mushy if boiled, but they retain their texture better when steamed. The inulin cannot be broken down by the human digestive system, but it is metabolised by bacteria in the colon. This can cause flatulence and, in some cases, gastric pain. Gerard’s Herbal, printed in 1621, quotes the English botanist John Goodyer on Jerusalem artichokes: “Which way soever they be dressed and eaten, they stir and cause a filthy loathsome stinking wind within the body, thereby causing the belly to be pained and tormented, and are a meat more fit for swine than men.” 

Jerusalem artichokes have 650 mg potassium per 1 cup (150g) serving. They are also high in iron, and contain 10-12% of the US RDA of fiber, niacin, thiamine, phosphorus and copper. Jerusalem artichokes can be used as animal feed, but they must be washed before being fed to most animals. Pigs can forage, however, and safely eat them directly from the ground. The stalks and leaves can be harvested and used for silage, though cutting the tops greatly reduces the harvest of the roots.

In Baden-Württemberg, Germany, over 90% of the Jerusalem artichoke crop is used to produce a spirit called “Topinambur”. By the end of the 19th-century, Jerusalem artichokes were being used in Baden to make a spirit called “Jerusalem Artichoke Brandy”, “Erdäpfler”, “Rossler”, or "Borbel". Jerusalem artichoke brandy smells fruity and has a slight nutty-sweet flavour. It is characterised by an intense, pleasing, earthy note. The tubers are washed and dried in an oven before being fermented and distilled. It can be further refined to make “Red Rossler” by adding common tormentil (Potentilla erecta), and other ingredients such as currants, to produce a somewhat bitter and astringent decoction. It is used as digestif, as well as a remedy for diarrhoea or abdominal pain.

In the language of flowers, Jerusalem artichoke flowers mean “a short but happy life”. Flowerless foliage carries the meaning of “deception”.

This post is part the Floral Friday Fotos meme.


  1. I don't think I've ever eaten a Jerusalem artichokes

  2. Interesting information. I had no clue before what they were, but I had heard the name before.