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Asteraceae FAMILY

Smallanthus sonchifolius

Smallanthus sonchifolius

Edibility
4/5
Medicinal
0/5

Safety & Hazards

None known

Cultivation Details

HabitPerennial
GrowthFast

Smallanthus sonchifolius is a plant of higher elevations in the tropics, where it is found at elevations up to 3,600 metres. It grows best in areas where annual daytime temperatures are within the range 12 - 22°c, but can tolerate 5 - 30°c[1]. Top growth is killed by frost, but the dormant tuber can tolerate temperatures at least a little below freezing[PFAF]. The plant prefers a mean annual rainfall in the range 800 - 1,200mm, but tolerates 600 - 1,400mm[1]. In S. America, plants succeed in areas with annual rainfall varying from 900 - 3,500mm[2]. Growth is unaffected by day-length and so the plants can produce good yields of edible tubers in both tropical and temperate zones, so long as there is a sufficiently long growing season of 6 - 7 months[2]. Succeeds in full sun and in light shade[1]. For best results, this plant requires a warm position in a deep rich soil[3], though it survives even when growing in poor soils[2]. Prefers a pH in the range 5.5 - 6.5, tolerating 5 - 7[1]. Plants are fast-growing[2]. One report says that plants take 6 - 7 months to produce a crop from planting out[2], though on our Cornwall trial ground they have cropped quite well with a 5 month growing period[PFAF]. The roots are brittle and must be harvested with care to avoid damage[2]. The harvested roots can be stored for several months[2]. Plants have not been selected for flavour or yield, some roots can be exceedingly sweet whilst others are fairly bland[2]. Yields of 38 tonnes per hectare have been recorded in South America[2].

Propagation

Seed - sow mid winter in a warm greenhouse and only just cover the seed[3]. Prick out the seedlings into individual pots as soon as they are large enough to handle and plant them out after the last expected frosts. Consider giving them some protection such as a cloche until they are growing away well. Plants do not usually produce flowers in Britain and therefore seed has to be obtained from other countries[PFAF]. Division in autumn. The plant forms 2 distinct types of tuber. Large tubers, usually on thin roots 2 - 5cm long, are used as storage organs and do not have the capacity to form new shoots. These are the tubers that are usually eaten. Smaller tubers are formed in a cluster around the stem. These form the shoots for the following year's growth and so are the ones that should be stored. Dig up the plants in the autumn once the top growth has been cut down by frost. Remove the large tubers for food, cut the main stems back to about 10cm long and store these stems with their cluster of small tubers in a cool frost-free place. Do not let them dry out. Pot them up in early spring in a greenhouse. When they come into active growth divide each cluster into individual shoots with their tubers attached and repot these. Plant them out in late spring after the last expected frosts[PFAF]. Cuttings of basal shoots in early spring in a warm greenhouse[3]. Harvest the shoots with plenty of underground stem when they are about 8 - 10cm above the ground. 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. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Smallanthus+sonchifolius>

Pollinators

Insects

References

  1. [1]Ecocrop — http://ecocrop.fao.org/ecocrop/srv/en/home ↩︎Basic information on a wide range of useful plants, plus details of environmental needs where available.
  2. [2]Lost Crops of the Incas — Popenoe. H. et al · National Academy Press · 1990 · ISBN 0-309-04264-X ↩︎An excellent book. Very readable, with lots of information and good pictures of some lesser known food plants of S. America.
  3. [3]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
  4. [4]A Taxonomic Study of Polymnia (Compositae) — Wells J.R. · 1965 · https://doi.org/10.2307/2805240 ↩︎
  5. [5]Vegetables in the Tropics — Tindall. H. D. · MacMillan, Oxford. · 1983 · ISBN 0-333-24268-8 ↩︎An excellent, in-depth look at the main vegetable crops that can be grown in the Tropics, plus many less well-known plants.
  6. [6]Alternative Foods. — Sholto-Douglas. J. ↩︎Not very comprehensive, it seems more or less like a copy of earlier writings with little added.
  7. [7]Dictionary of Economic Plants. — Uphof. J. C. Th. · Weinheim · 1959 · ISBN - ↩︎An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
  8. [8]A Dictionary of Plants Used by Man. — Usher. G. · Constable · 1974 · ISBN 0094579202 ↩︎Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
  9. [9]The Ethno-Botany of Pre-Columbian Peru. — Towle. M. A. · Aldine Publishing Co. Chicago. · 1961 ↩︎A very interesting book covering quite a lot of information on plant uses in S. America although many of the plants are not suitable for temperate areas.
  10. [10]Cornucopia - A Source Book of Edible Plants. — Facciola. S. · Kampong Publications · 1990 · ISBN 0-9628087-0-9 ↩︎Excellent. Contains a very wide range of conventional and unconventional food plants (including tropical) and where they can be obtained (mainly N. American nurseries but also research institutes and a lot of other nurseries from around the world.
  11. [PFAF]Plants for a Future — pfaf.org ↩︎