|Helianthus tuberosus subsp. var.||Jerusalem artichoke, sunroot, sunchoke, earth apple, topinambur|
The Jerusalem artichoke (Helianthus tuberosus), also called the sunroot or sunchoke or earth apple or topinambur, is a species of sunflower native to the eastern United States, from 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.
It is a herbaceous perennial plant growing to 1.5–3 m tall with opposite leaves on the lower part of the stem becoming alternate higher up. The leaves have a rough, hairy texture and the larger leaves on the lower stem are broad ovoid-acute and can be up to 30 cm long and the higher leaves smaller and narrower.
The tubers are elongated and uneven, typically 7.5–10 cm long and 3–5 cm thick, and vaguely resembling ginger root, with a crisp texture when raw. They vary in color from pale brown to white, red or purple.
It is hardy to zone 4 and is not frost tender. It is in flower in October, and the seeds ripen in November. The flowers are hermaphrodite (have both male and female organs) and are pollinated by Bees, flies.
|Standard Cyclopedia of Horticulture|
Jerusalem Artichoke (Helianthus tuberosus, Linn.). Compositae. The Jerusalem artichoke is the subterranean stem tuber of a native sunflower. Fig. 391. The plant is coarse and upright, and persists as a weed when once introduced. It does not need excessively rich soil, nor high culture, succeeding on any warm well-drained land without attention. It is planted much after the manner of potatoes, and it will grow and produce its many smallish, white, edible tubers.
In late fall, the plants may be pulled up, exposing to view the tubers that are clustered around the roots near the main stalks so that they can be easily gathered with the help of a hoe or potato hook, if wanted for use as a culinary vegetable; or, if grown for hog-feed, the hogs may be turned right into the field and allowed to dig their own. All farm stock seems to like the artichoke tubers. If shredded or ground and mixed with meals, they make a good winter ration, as a variety, for poultry. More prolific than common potatoes, and far more easily grown, the artichoke is one of the crops that may be considered for cultivation as a succulent vegetable to - feed to cattle, swine, and other farm animals during winter. Raw or boiled and served cold with oil and vinegar, this tuber also makes a very palatable winter or spring salad, and for this purpose it finds a limited sale in our markets. The chief commercial demand for it is for seed purposes. Frost has no injurious effect on the tuber in the ground, and the easiest way to winter it, therefore, is by leaving the plants alone until spring and then digging the tubers. If already harvested, they may be pitted like potatoes, beets, or other roots, and will require very little covering. Mammoth White French is said by some propagators to be an improved strain of the Jerusalem artichoke. If there is danger of the plant spreading and becoming a weed, hogs, when given a chance at it, will soon clear the land of the tubers. It was cultivated by the Indians. See Helianthus.
Jerusalem artichokes are easy to cultivate, which tempts gardeners to simply leave them completely alone to grow. However the quality of the edible tubers degrades unless the plants are dug up and replanted in fertile soil. This can be a chore, as even a small piece of tuber will grow if left in the ground, making the hardy plant a potential weed.
The plant prefers light (sandy), medium (loamy) and heavy (clay) soils, requires well-drained soil and can grow in nutritionally poor soil. The plant prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires dry or moist soil. The plant can tolerates strong winds but not maritime exposure.
A very easily grown plant, it grows best in a loose circumneutral loam but succeeds in most soils and conditions in a sunny position[1, 16, 37, 38, 269]. Plants are more productive when grown in a rich soil[1, 37, 38]. 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[4, 46, 183, 200]. 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[K]. 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.
Seed - sow spring in a cold frame. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Division in spring or autumn. Harvest the tubers in late autumn or the winter and either replant the tubers immediately or store them in a cool but frost-free place and plant them out in early spring. Jerusalem artichoke is propagated by tubers, which should be planted as early as possible in the spring when the soil can be satisfactorily worked. Late planting usually reduces tuber yields and size seriously. Whole tubers or pieces about 50 g (2 oz.) should be planted like potatoes and covered to a depth of 10 cm. Pieces larger than 50 g do not increase the yield, though those smaller will decrease it. Deeper planting may delay emergence, weaken the sprouts, and cause the tubers to develop deeper, making harvest more difficult. Basal cuttings in spring. Harvest the shoots when they are about 10 - 15cm long with plenty of underground stem. Pot them up into individual pots and keep them in light shade in a cold frame or greenhouse until they are rooting well. Plant them out in the summer.
Pests and diseases
- 'Boston Red'
- 'Dwarf Sunray' - Tubers are so crisp and tender that no peeling of the outer skin is necessary. A relatively low-growing cultivar, 1.5 - 2 metres tall. Unlike other cultivars, this form usually flowers freely.
- 'Fuseau' - Long tapered tubers 10 - 12cm long and up to 4cm wide. Very smooth and free from the knobs that characterize most Jerusalem Artichokes, thus making them easier to clean.
- 'Long Red' - Large tapered tubers that are free from the knobs that make cleaning Jerusalem Artichokes so difficult.
- 'Stampede' - The white-skinned tubers are large, sometimes weighing more than 250 grams each. A special high-yielding, extra early strain, maturing a month or more before other cultivars. Relatively dwarf, growing to 1.8 metres tall. It is winter hardy even in severe cold.
- ↑ Germplasm Resources Information Network: Helianthus tuberosus
- ↑ Purdue University Center for New Crops & Plants Products: Helianthus tuberosus
- Plants for a Future - source of some creative commons text
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963