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Brassicaceae FAMILY

Brassica napus

Brassica napus

Edibility
3/5
Medicinal
2/5

Safety & Hazards

The oil contained in the seed of some varieties of this species can be rich in erucic acid which is used in industry but is toxic if consumed. However, modern cultivars have been selected for culinary use which are almost free of erucic acid[1].

Cultivation Details

HabitAnnual/Biennial
Growth—

Brassica napus is a plant of the temperate zone, much cultivated in temperate regions and also in the subtropics and sometimes at higher elevations in the tropics. Succeeds in full sun in a well-drained fertile preferably alkaline soil[2]. Succeeds in any reasonable soil[3]. Prefers a heavy soil and cool moist conditions[4, 5]. Sunny days and cool nights are favourable for plant growth whilst dry weather at harvest time is essential[6]. Colza is reported to tolerate a pH in the range of 4.2 to 8.2[6]. Brassica napus is an aggregate species, probably derived through cultivation. It is thought that crosses of Brassica oleracea with Brassica rapa gave rise to the subspecies Brassica napus pabularia, from which the subspecies napus and rapifera and other cvs were derived[6]. Theere are individual records for all the following forms:- Brassica napus subsp napus. The oilseed rapes, sometimes further subdivided into spring-sown and autumn-sown forms. Brassica napus subsp rapifera. Rutabaga or Swede. Often grown commercially and in gardens for its edible swollen root. Brassica napus subsp pabularia. Rape kale or Siberian kale. Cultivated as a vegetable for its leaves. The oil obtained from the seed is high in erucic acid and glucosinolates, both of which have anti-nutritional properties. Cultivars have been developed that have a low content of these items and are therefore suitable for food. Colza is 70% self-pollinating and 30% cross-pollinated. Even if wind and insects are absent, seed are still produced. Yield increases with honeybees[6]. This species is closely related to Brassica rapa[2].

Propagation

Seed - sow in situ in early spring to mid-August for a green manure crop. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Brassica+napus>

Pollinators

Bees, Self

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]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.
  3. [3]Salads all the Year Round. — Larkcom. J. · Hamlyn · 1980 ↩︎A good and comprehensive guide to temperate salad plants, with full organic details of cultivation.
  4. [4]New Vegetable Growers Handbook. — Simons. · Penguin · 1977 · ISBN 0-14-046-050-0 ↩︎A good guide to growing vegetables in temperate areas, not entirely organic.
  5. [5]Companion Planting for Successful Gardening. — Riotte. L. · Garden Way, Vermont, USA. · 1978 · ISBN 0-88266-064-0 ↩︎Fairly good.
  6. [6]Handbook of Energy Crops — Duke. J. · - · 1983 · https://hort.purdue.edu/newcrop/duke_energy/dukeindex.html · ISBN - ↩︎Published only on the Internet, excellent information on a wide range of both temperate and tropical plants.
  7. [7]Pacific Island Ecosystems at Risk — http://www.hear.org/pier/scientificnames/index.html ↩︎A very good website detailing weed species that have been introduced into the Pacific Islands.
  8. [8]Flora of the British Isles. — Clapham, Tutin and Warburg. · Cambridge University Press · 1962 · ISBN - ↩︎A very comprehensive flora, the standard reference book but it has no pictures.
  9. [9]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
  10. [10]The Oxford Book of Food Plants. — Harrison. S. Wallis. M. Masefield. G. · Oxford University Press · 1975 · ISBN - ↩︎Good drawings of some of the more common food plants from around the world. Not much information though.
  11. [11]The Gardener's Assistant. — Thompson. B. · Blackie and Son. · 1878 · ISBN - ↩︎Excellent general but extensive guide to gardening practices in the 19th century. A very good section on fruits and vegetables with many little known species.
  12. [12]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.
  13. [13]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.
  14. [14]Hamlyn Encyclopaedia of Plants. — Triska. Dr. · Hamlyn · 1975 · ISBN 0-600-33545-3 ↩︎Very interesting reading, giving some details of plant uses and quite a lot of folk-lore.
  15. [15]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.
  16. [16]Glossary of Indian Medicinal Plants (Including the Supplement). — Chopra. R. N., Nayar. S. L. and Chopra. I. C. · Council of Scientific and Industrial Research, New Delhi. · 1986 · ISBN - ↩︎Very terse details of medicinal uses of plants with a wide range of references and details of research into the plants chemistry. Not for the casual reader.
  17. [17]The Herb Book. — Lust. J. · Bantam books · 1983 · ISBN 0-553-23827-2 ↩︎Lots of information tightly crammed into a fairly small book.
  18. [18]Plants for Man. — Schery. R. W. ↩︎Fairly readable but not very comprehensive. Deals with plants from around the world.
  19. [19]Plants Consumed by Man. — Brouk. B. · Academic Press · 1975 · ISBN 0-12-136450-x ↩︎Readable but not very comprehensive.