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Fabaceae FAMILY

Glycyrrhiza glabra

Glycyrrhiza glabra

Edibility
4/5
Medicinal
5/5

Safety & Hazards

Whilst licorice is basically a very safe and effective medicine, when used over a long period or in large quantities it can raise the blood pressure. A gross overdose of the root can cause oedema, high blood pressure and congestive heart failure[1, 2].

Cultivation Details

HabitPerennial
Growth—

Glycyrrhiza glabra is a plant of the temperate zone, where it is found at elevations up to 1,300 metres. It grows best in areas where annual daytime temperatures are within the range 14 - 25°c, but can tolerate 5 - 30°c[3]. When dormant, the plant can survive temperatures down to about -15°c, but young growth in spring is more tender and can be severely damaged at 0°c[4, 3]. It prefers a mean annual rainfall in the range 500 - 1,000mm, but tolerates 300 - 1,200mm[3]. Requires a deep well cultivated fertile moisture-retentive soil for good root production[4]. Prefers a sandy soil with abundant moisture and does not flourish in clay[5]. Prefers a pH in the range 6.5 - 7.5, tolerating 5.5 - 8.2[3]. Slightly alkaline conditions produce the best plants[6]. The plant thrives in a maritime climate[7] and can tolerate moderate levels of soil salinity[3]. Liquorice is often cultivated for its edible root which is widely used in medicine and as a flavouring. There are some named varieties[8]. The ssp. glandulifera grows in Russia and produces adventitious roots up to 10 cm thick[9]. Yields of 10 - 12 tonnes per hectare were considered good in the early 20th century, this only being attained in the fourth year of growth[5]. Yields of fresh root can reach 20 - 50 tonnes per hectare when harvested every 2 - 3 years[3]. Unless seed is required, the plant is usually prevented from flowering so that it puts more energy into producing good quality roots[6]. The bruised root has a characteristic sweet pungent smell[10]. Plants are slow to settle in and do not produce much growth in their first two years after being moved[5]. The young growth is also very susceptible to damage by slugs and so the plant will require some protection for its first few years[PFAF]. A fairly deep-rooting plant, the roots are up to 120cm long[5]. It can be difficult to eradicate once it is established[6]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[4].

Propagation

Pre-soak the seed for 24 hours in warm water and then sow spring or autumn in a greenhouse[4]. Prick out the seedlings into individual pots when they are large enough to handle, and grow them on for their first winter in a greenhouse. Plant out in late spring or early summer when in active growth. Plants are rather slow to grow from seed[6]. Division of the root in spring or autumn. Each division must have at least one growth bud. Autumn divisions can either be replanted immediately or stored in clamps until the spring and then be planted out[4]. It is best to pt up the smaller divisions and grow them on in a cold frame until they are established before planting them out in the spring or summer. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Glycyrrhiza+glabra>

Pollinators

Insects

References

  1. [1]Edible and Medicinal Plants. — Launert. E. · Hamlyn · 1981 · ISBN 0-600-37216-2 ↩︎Covers plants in Europe. a drawing of each plant, quite a bit of interesting information.
  2. [2]A Colour Atlas of Poisonous Plants. — Frohne. D. and Pfänder. J. · Wolfe · 1984 · ISBN 0723408394 ↩︎Brilliant. Goes into technical details but in a very readable way. The best work on the subject that I've come across so far.
  3. [3]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.
  4. [4]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.
  5. [5]A Modern Herbal. — Grieve. · Penguin · 1984 · ISBN 0-14-046-440-9 ↩︎Not so modern (1930's?) but lots of information, mainly temperate plants.
  6. [6]Encyclopaedia of Herbs and their Uses. — Bown. D. · Dorling Kindersley, London. · 1995 · ISBN 0-7513-020-31 ↩︎A very well presented and informative book on herbs from around the globe. Plenty in it for both the casual reader and the serious student. Just one main quibble is the silly way of having two separate entries for each plant.
  7. [7]Encyclopaedia of Medicinal Plants. — Chiej. R. · MacDonald · 1984 · ISBN 0-356-10541-5 ↩︎Covers plants growing in Europe. Also gives other interesting information on the plants. Good photographs.
  8. [8]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.
  9. [9]Plants Consumed by Man. — Brouk. B. · Academic Press · 1975 · ISBN 0-12-136450-x ↩︎Readable but not very comprehensive.
  10. [10]Scented Flora of the World. — Genders. R. · Robert Hale. London. · 1994 · ISBN 0-7090-5440-8 ↩︎An excellent, comprehensive book on scented plants giving a few other plant uses and brief cultivation details. There are no illustrations.
  11. [11]Flora of the USSR. — Komarov. V. L. · Israel Program for Scientific Translation · 1968 · http://www.biodiversitylibrary.org · ISBN - ↩︎An immense (25 or more large volumes) and not yet completed translation of the Russian flora. Full of information on plant uses and habitats but heavy going for casual readers. It can be downloaded from the Internet.
  12. [12]Flora of China — Missouri Botanical Garden Press; St. Louis. · 1994 · http://flora.huh.harvard.edu/china/ ↩︎An excellent, comprehensive resource in 25 volumes. In addition to the botanical information the flora also gives basic information on habitat and some uses. An on-line version is also available.
  13. [13]Flora Europaea — ? · Cambridge University Press · 1964 · ISBN - ↩︎An immense work in 6 volumes (including the index). The standard reference flora for Europe, it is very terse though and with very little extra information. Not for the casual reader.
  14. [14]Fruits of the Earth. — Bianchini. F., Corbetta. F. and Pistoia. M. ↩︎Lovely pictures, a very readable book.
  15. [15]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.
  16. [16]Flowers of Europe - A Field Guide. — Polunin. O. · Oxford University Press · 1969 · ISBN 0192176218 ↩︎An excellent and well illustrated pocket guide for those with very large pockets. Also gives some details on plant uses.
  17. [17]Economic Botany. — Hill. A. F. · The Maple Press · 1952 · ISBN - ↩︎Not very comprehensive, but it is quite readable and goes into some detail about the plants it does cover.
  18. [18]The Herb Book. — Lust. J. · Bantam books · 1983 · ISBN 0-553-23827-2 ↩︎Lots of information tightly crammed into a fairly small book.
  19. [19]The Encyclopedia of Medicinal Plants — Chevallier. A. · Dorling Kindersley. London · 1996 · ISBN 9-780751-303148 ↩︎An excellent guide to over 500 of the more well known medicinal herbs from around the world.
  20. [20]Constituent Properties of Licorices Derived from Glycyrrhiza uralensis, G. glabra, or G. inflata Identified by Genet — Kenji Kondo; Mao Shiba; Rie Nakamura; Takashi Morota & Yukih · 2007 · http://10.1248/bpb.30.1271 ↩︎
  21. [21]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.
  22. [22]The Dictionary of Modern Herbalism. — Mills. S. Y. ↩︎An excellent small herbal.
  23. [23]Chinese Materia Medica. — Stuart. Rev. G. A. · Taipei. Southern Materials Centre · 1911 · ISBN - ↩︎A translation of an ancient Chinese herbal. Fascinating.
  24. [24]CosIng — http://ec.europa.eu/growth/tools-databases/cosing/ ↩︎CosIng is the European Commission database for information on cosmetic substances and ingredients.
  25. [PFAF]Plants for a Future — pfaf.org ↩︎