PlantPeers
Back to Catalog
No image available
Asparagaceae FAMILY Least Concern

Yucca glauca

Yucca glauca

Edibility
2/5
Medicinal
2/5

Safety & Hazards

The roots contain saponins[1]. Although poisonous, saponins also have a range of medicinal applications and many saponin-rich plants are used in herbalism (particularly as emetics, expectorants and febrifuges) or as sources of raw materials for the pharmaceutical industry. Saponins are also found in a number of common foods, such as many beans. Saponins have a quite bitter flavour and are in general poorly absorbed by the human body, so most pass through without harm. They can be removed by carefully leaching in running water. Thorough cooking, and perhaps changing the cooking water once, will also normally remove most of them. However, it is not advisable to eat large quantities of raw foods that contain saponins. Saponins are much more toxic to many cold-blooded creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish and make them easy to catch[PFAF].

Cultivation Details

HabitEvergreen Shrub
GrowthSlow

Yucca glauca is a plant of semi-arid regions in southern N. America and, although capable of tolerating occasional short-lived temperatures down to around -15°c, does not grow very well in moist climates, being especially intolerant of winter wet[2]. Another report says that it can tolerate occasional temperatures to about -30°c so long as the climate is dry[3]. Thrives in most soils but prefers a sandy loam and full exposure to the south[4]. Dislikes chalky or peaty soils[5]. Can succeed in light shade[PFAF]. Plants are hardier when grown on poor sandy soils[2]. Prefers a hot dry position and a poor soil[6]. Established plants are very drought tolerant[2]. A very ornamental plant[7], it rarely flowers unless in a dry sandy soil[8]. The scent of the flowers is most pronounced at night[9]. Yuccas are pollinated by small, white Yucca moths (Tegeticula yucasella and related species) with which they have a special plant-insect mutualism. At night, the fragrant flowers attract the female moth that feeds on the nectar. She then rolls pollen from the flowers into a ball that is three times the size of her head and carries the pollen ball to the next flower. There, she first lays eggs inside the immature ovary and then deposits the pollen on the flower’s stigma ensuring that seeds will form to feed her progeny. Because the larvae mature before they are able to consume all of the seeds (60 to 80% of the seeds remain viable), the plants are able to reproduce as well[10]. In regions where the moth cannot live and, if fruit and seed are required, then hand pollination is necessary[2]. This can be quite easily and successfully done using something like a small paint brush. Individual crowns are monocarpic, dying after flowering[11]. However, the crown will usually produce a number of sideshoots before it dies and these will grow on to flower in later years[11]. Plants in this genus are notably resistant to honey fungus[2]. Members of this genus seem to be immune to the predations of rabbits[11]

Propagation

Seed - sow spring in a greenhouse. Pre-soaking the seed for 24 hours in warm water may reduce the germination time. It usually germinates within 1 - 12 months if kept at a temperature of 20°c. Prick out the seedlings into individual pots when they are large enough to handle and grow them on in the greenhouse or cold frame for at least their first two winters. Plant them out into their permanent positions in early summer and consider giving them some winter protection for at least their first winter outdoors - a simple pane of glass is usually sufficient[PFAF]. Seed is not usually produced when plants are grown outside their native range unless the flowers are hand pollinated. Root cuttings in late winter or early spring. Lift in mid spring and remove small buds from base of stem and rhizomes. Dip in dry wood ashes to stop any bleeding and plant in a sandy soil in pots in a greenhouse until established[12]. Division of suckers in late spring. Larger divisions can be planted out direct into their permanent positions. We have found that it is best to pot up smaller divisions and grow them on in light shade in a greenhouse or cold frame until they are growing away well. Plant them out in the following spring. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Yucca+glauca>

Pollinators

Hand

References

  1. [1]A Field Guide to Medicinal Plants. Eastern and Central N. America. — Foster. S. & Duke. J. A. · Houghton Mifflin Co. · 1990 · ISBN 0395467225 ↩︎A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
  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]Growing from Seed. Volume 4. — Bird. R. (Editor) · Thompson and Morgan. · 1990 · ISBN - ↩︎Very readable magazine with lots of information on propagation. A good article on Yuccas, one on Sagebrush (Artemesia spp) and another on Chaerophyllum bulbosum.
  4. [4]Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. — Bean. W. · Murray · 1981 · ISBN - ↩︎A classic with a wealth of information on the plants, but poor on pictures.
  5. [5]Popular Hardy Perennials. — Sanders. T. W. · Collingridge · 1926 · ISBN - ↩︎A fairly wide range of perennial plants that can be grown in Britain and how to grow them.
  6. [6]The Milder Garden. — Taylor. J. · Dent · 1990 ↩︎A good book on plants that you didn't know could be grown outdoors in Britain.
  7. [7]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 ]).
  8. [8]Hardy Bulbs.; Including Half-hardy Bulbs and Tuberous and Fiberous-rooted Plants — Grey. C. H. · Williams & Norgate. · 1938 · ISBN - ↩︎Rather dated now, but an immense work on bulbs for temperate zones and how to grow them. Three large volumes.
  9. [9]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.
  10. [10]Plants Database — United States Department of Agriculture · http://plants.usda.gov/java/factSheet ↩︎An online database with an excellent collection of fact sheets about native N. American plants.
  11. [11]Perennial Garden Plants — Thomas. G. S. · J. M. Dent & Sons, London. · 1990 · ISBN 0 460 86048 8 ↩︎A concise guide to a wide range of perennials. Lots of cultivation guides, very little on plant uses.
  12. [12]Propagation of Trees, Shrubs and Conifers. — Sheat. W. G. · MacMillan and Co · 1948 · ISBN - ↩︎A bit dated but a good book on propagation techniques with specific details for a wide range of plants.
  13. [13]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
  14. [14]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
  15. [15]Gray's Manual of Botany.Eighth Edition — Fernald. M. L. · American Book Co.; New York · 1950 · ISBN 0442222505 ↩︎A bit dated but a good and concise flora of the eastern part of N. America.
  16. [16]Sturtevant's Edible Plants of the World. — Hedrick. U. P. · Dover Publications · 1972 · ISBN 0-486-20459-6 ↩︎Lots of entries, quite a lot of information in most entries and references.
  17. [17]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.
  18. [18]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.
  19. [19]Food Plants of the N. American Indians. — Yanovsky. E. · U.S. Depf of Agriculture. · ISBN - ↩︎A comprehensive but very terse guide. Not for the casual reader.
  20. [20]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
  21. [21]Edible Native Plants of the Rocky Mountains. — Harrington. H. D. · University of New Mexico Press · 1967 · ISBN 0-8623-0343-9 ↩︎A superb book. Very readable, it gives the results of the authors experiments with native edible plants.
  22. [22]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.
  23. [23]A Field Guide to N. American Edible Wild Plants. — Elias. T. and Dykeman. P. · Van Nostrand Reinhold · 1982 · ISBN 0442222009 ↩︎Very readable.
  24. [24]Yucca — 2007 · http://www.naturaldatabase.com/ ↩︎A very comprehensive database of herbs, minerals and other natural products taken to promote health
  25. [25]Yuccas of the Southwest — Webber J.M. · USDA · 1953 ↩︎Rather dated, but very detailed information on the various species and their uses
  26. [26]Earth Medicine, Earth Food. — Weiner. M. A. · Ballantine Books · 1980 · ISBN 0-449-90589-6 ↩︎A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical.
  27. [27]The Herb Book. — Lust. J. · Bantam books · 1983 · ISBN 0-553-23827-2 ↩︎Lots of information tightly crammed into a fairly small book.
  28. [28]Plants for Man. — Schery. R. W. ↩︎Fairly readable but not very comprehensive. Deals with plants from around the world.
  29. [29]Manual of the Trees of N. America. — Sargent. C. S. · Dover Publications Inc. New York. · 1965 · http://www.biodiversitylibrary.org/ · ISBN 0-486-20278-X ↩︎Two volumes, a comprehensive listing of N. American trees though a bit out of date now. Good details on habitats, some details on plant uses. Not really for the casual reader. It can be downloaded from the internet.
  30. [30]A Weavers Garden — Buchanan. R. · McGraw-Hill Contemporary · 1987 · ISBN 0934026289 ↩︎Covers all aspects of growing your own clothes, from fibre plants to dyes.
  31. [31]Early Uses of Californian Plants. — Balls. E. K. · University of California Press · 1975 · ISBN 0-520-00072-2 ↩︎A nice readable book.
  32. [32]Edible and Useful Wild Plants of the United States and Canada. — Saunders. C. F. · Dover Publications · 1976 · ISBN 0-486-23310-3 ↩︎Useful wild plants of America. A pocket guide.
  33. [PFAF]Plants for a Future — pfaf.org ↩︎