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Bidens pilosa
Asteraceae FAMILY

Bidens pilosa

Bidens pilosa

Edibility
2/5
Medicinal
3/5

Safety & Hazards

The roots, leaves and flowers are strongly phototoxic, the achenes weakly so[1]. Substances isolated from the leaves can kill human skin in the presence of sunlight at concentrations as low as 10ppm[1].

Cultivation Details

HabitAnnual
Growth—

Bidens pilosa is a pantropical weed, often also extending into the temperate zone, where it can be found at elevations up to 3,600 metres[2]. It prefers temperatures above 15°c and below 45°c, but is tolerant to frosts and has roots capable of withstanding and regenerating after short-lived temperatures falling as low as -15°c[2]. It can succeed in areas where the mean annual rainfall is in the range 500 - 3,500mm[2]. Succeeds in any moderately fertile moisture-retentive soil in full sun[3]. Plants can grow in a vast range of habitats ranging from moist soil, sand, lime rock, or dry, infertile soil[2]. Plants are tolerant of a pH range from 4 - 9 and also highly saline soils[2]. Plants can tolerate severe droughts[2].A fast-growing plant, flowering starts 6 weeks after emergence and continues until plant senescence 2 - 3 months later[4]. The plants are ready for harvesting within 4 - 6 weeks of emergence, before seed setting. Harvesting is done by hand picking, cutting or uprooting. If the plants are topped, a second harvest can follow after 2 weeks. Up to 6 harvests are possible[4]. There may be 4 or 5 successive plantings within a year[4]. If it is grown for harvesting the leaves as antimalaria medicine, deflowering is necessary to retard senescence and maintain growth[4]. Yields of up to 30 tonnes per hectare can be obtained[4]. The plant is not fire tolerant but is known to quickly invade burnt areas by means of its seeds[2].

Propagation

Seed - sow early spring in a greenhouse and only just cover the seed. The optimum temperature for germination is 25 - 30°c, temperatures below 15°c and above 45°c are not favourable[4]. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in May. Alternatively, a sowing in situ in mid to late spring can be tried. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Bidens+pilosa>

Pollinators

Bees, Hoverflies, Self

References

  1. [1]Medicinal Plants of China — Duke. J. A. and Ayensu. E. S. · Reference Publications, Inc. · 1985 · ISBN 0-917256-20-4 ↩︎Details of over 1,200 medicinal plants of China and brief details of their uses. Often includes an analysis, or at least a list of constituents. Heavy going if you are not into the subject.
  2. [2]Global Invasive Species Database — http://www.issg.org/database/welcome/ ↩︎Very detailed information on almost 400 species (with more being added) of plants that have become weeds in areas outside their native range.
  3. [3]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
  4. [4]Protabase - Plant Resources of Tropical Africa. — http://www.prota.org ↩︎An excellent on-line database with detailed information on over 3,200 species of useful plants of Africa.
  5. [5]Flora of New Zealand. — Allan. H. H. · Government Printer, Wellington. · 1961 · http://floraseries.landcareresearch.co.nz/pages/Book.aspx?fileName=Flora%201.xml · ISBN - ↩︎The standard work, in 5 volumes though only the first two are of interest to the plant project. Very good on habitats. There is also an on-line version.
  6. [6]Plants and People of Nepal — Manandhar. N. P. · Timber Press. Oregon. · 2002 · ISBN 0-88192-527-6 ↩︎Excellent book, covering over 1,500 species of useful plants from Nepal together with information on the geography and peoples of Nepal. Good descriptions of the plants with terse notes on their uses.
  7. [7]Plants for Human Consumption. — Kunkel. G. · Koeltz Scientific Books · 1984 · ISBN 3874292169 ↩︎An excellent book for the dedicated. A comprehensive listing of Latin names with a brief list of edible parts.
  8. [8]Edible Wild Plants of Tanzania — Ruffo, C.K.: Birnie, A. & Tengnas, B. · Regional Land Management Unit; Nairobi. · 2002 · ISBN 9966-896-60-0 ↩︎A very well presented, simple guide to growing and utilizing wild food plants in Tanzania, with line drawings of each plant, a description, habitat and range, non-food as well as food uses, plus basic information on growing the plants.
  9. [9]Native Edible Plants of New Zealand. — Crowe. A. · Hodder and Stoughton · 1990 · ISBN 0-340-508302 ↩︎A very well written and illustrated book based on the authors own experiments with living on a native diet.
  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. [11]Plant Resources of Southeast Asia — http://proseanet.org/ ↩︎Lots of information on the uses of the plants of SE Asia.
  12. [12]Medicinal Plants of the Guianas — DeFilipps, R. A.; Maina, S. L.; & Crepin, J. · Smithsonian Museum · http://botany.si.edu/bdg/medicinal/index.html ↩︎A down-loadable PDF document of a book in pre-publication awaiting illustration. An excellent, if rather terse, guide to the traditional medicinal uses of the plants of the region