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Iridaceae FAMILY

Iris japonica

Iris japonica

Edibility
1/5
Medicinal
2/5

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—

Prefers a gritty well-drained soil with plenty of moisture in summer and shelter from early morning sun[3, 4]. Prefers a lime-free soil but succeeds in most good soils[5, 6]. Succeeds in full sun or partial shade[5], but plants flower better in a hot sunny position[7]. Established plants are drought tolerant[7]. Cultivated for its edible root in Japan[8]. A number of named varieties have been selected for their ornamental value[9]. It is best to lift the plant in October, store in sand in a cool frost-free place over winter and plant out in March[3]. Plants have creeping aerial rhizomes that root at intervals[9]. The flowers are susceptible to damage by late frosts, the plants failing to flower after an exceptionally cold winter[9]. Members of this genus are rarely if ever troubled by browsing deer or rabbits[10].

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 mid summer. 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+japonica>

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]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 ]).
  4. [4]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.
  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]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.
  7. [7]The Dry Garden. — Chatto. B. · Dent · 1982 · ISBN 0460045512 ↩︎A good list of drought resistant plants with details on how to grow them.
  8. [8]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.
  9. [9]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.
  10. [10]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.
  11. [11]Flora of Japan. (English translation) — Ohwi. G. · Smithsonian Institution · 1965 · ISBN - ↩︎The standard work. Brilliant, but not for the casual reader.
  12. [12]Tanaka's Cyclopedia of Edible Plants of the World. — Tanaka. T. & Nakao S. · Keigaku Publishing; Tokyo · 1976 · ISBN - ↩︎The most comprehensive list of edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.
  13. [13]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.
  14. [14]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.
  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.