PlantPeers
Back to Catalog
No image available
Iridaceae FAMILY

Iris douglasiana

Iris douglasiana

Edibility
0/5
Medicinal
0/5

Safety & Hazards

Many plants in this genus are thought to be poisonous if ingested, so caution is advised[1]. The roots are especially likely to be toxic[2]. Plants can cause skin irritations and allergies in some people[2].

Cultivation Details

HabitEvergreen Perennial
Growth—

We have found this species to be exceedingly easy to grow in sun or shade in our medium loamy soil that is slightly acid. It does well in very wet as well as very dry years. It has withstood considerable neglect, forming a very dense clump that seems capable of standing up to grass and other vigorous plants[PFAF]. The following notes, however, suggest a wide difference of opinions over the best conditions for this plant[PFAF]. Requires a rich well-drained lime-free soil[3, 4, 5]. Another report says that it succeeds in sun or shade in acid or slightly alkaline soils[6]. Requires a moist soil, growing well by water[7]. This species requires a really well-drained soil, dry rather than damp[8]. It succeeds in dry shade according to another report which also says that it is drought tolerant once established[9]. Easily grown in semi-shade in a woodland soil[3]. Tolerates salt spray[6]. Plants are hardy to about -15°c[10]. A very variable and ornamental plant[7, 11], it hybridizes readily, especially with other Pacific coast Irises[6]. Iris douglasiana hybridizes with I. bracteata, I. chrysophylla, I. fernaldii, I. hartwegii, I. innominata, I. macrosiphon, I. munzii, I. purdyi, I. tenax, and I. tenuissima[11]. Members of this genus are rarely if ever troubled by browsing deer or rabbits[8]. Resents root disturbance, any moving of the plant is best done in early September[6].

Propagation

Seed - best sown as soon as it is ripe in a cold frame. Stored seed should be sown as early in the year as possible in a cold frame. 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 their first year. Plant out into their permanent positions in late spring or early summer. Division, best done after flowering in late summer[3]. Very easy, larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Iris+douglasiana>

Pollinators

Insects

References

  1. [1]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.
  2. [2]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.
  3. [3]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.
  4. [4]A California Flora. — Munz P.A. & Keck D.D. · University of California Press; Los Angeles · 1959 · ISBN - ↩︎An excellent flora but no pictures. Not for the casual reader.
  5. [5]The World of Iridaceae — Innes. C. ↩︎Deals with many of the plants in the Iris family giving brief details of habitat and notes on cultivation. Well illustrated.
  6. [6]Alpine Garden Society Bulletin. Volume 56. — ? · Alpine Garden Society · ISBN - ↩︎Excerpts from the periodical. Some details on Corydalis spp.
  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]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.
  9. [9]The Dry Garden. — Chatto. B. · Dent · 1982 · ISBN 0460045512 ↩︎A good list of drought resistant plants with details on how to grow them.
  10. [10]Perennials. Volumes 1 and 2. — Phillips. R. & Rix. M. · Pan Books · 1991 · ISBN 0-330-30936-9 ↩︎Photographs of over 3,000 species and cultivars of ornamental plants together with brief cultivation notes, details of habitat etc.
  11. [11]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.
  12. [12]Early Uses of Californian Plants. — Balls. E. K. · University of California Press · 1975 · ISBN 0-520-00072-2 ↩︎A nice readable book.
  13. [13]The History and Folklore of North American Wild Flowers. — Coffey. T. · Facts on File. · 1993 · ISBN 0-8160-2624-6 ↩︎A nice read, lots of information on plant uses.
  14. [14]Plant Fibres for Papermaking. — Bell. L. A. · Liliaceae Press · 1988 · ISBN - ↩︎A good practical section on how to make paper on a small scale plus details of about 75 species (quite a few of them tropical) that can be used.
  15. [15]Plants for Ground Cover — Thomas. G. S. · J. M. Dent & Sons · 1990 · ISBN 0-460-12609-1 ↩︎An excellent detailled book on the subject, very comprehensive.
  16. [PFAF]Plants for a Future — pfaf.org ↩︎