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Common Name: Japanese Water Iris

General Information

Iris ensata is a perennial plant that can grow up to 0.60 metres tall.
It is harvested from the wild for local use as a food, medicine and source of materials.

Known Hazards

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

Botanical References

,

Range

E. Asia - China, Japan, Korea, Siberia.

Habitat

Dry sandy plains near lakes, meadows, clay-solonetz places in steppes and solonetz meadows[]. Marshes, ditches and wet grassy places[].

Properties

Edibility Rating
Medicinal Rating
Habit	Perennial
Height	0.60 m
Pollinators	Insects
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Prefers a light well-drained soil and a sunny position[]. Prefers partial shade[]. Likes plenty of moisture and a rich loamy slightly acid soil[, ]. Requires a lime-free soil[]. Some cultivars, in particular the 'Higo' strain, tolerate a pH up to 7.4[]. Plants can be grown in containers in pond margins but are then best kept in drier conditions over winter[].
This species is hardy to about -20°c[].
Cultivated for its root in Japan[]. (for the starch).
There are many named varieties, selected for their ornamental value[, ].
Members of this genus are rarely if ever troubled by browsing deer or rabbits[].

Edible Uses

Root - the source of an edible starch[, , ]. Some caution is advised, see the notes above on toxicity.

Medicinal

The root is alterative, anthelmintic, antidote, appetizer, depurative, diuretic, hepatic and vermifuge[, , ]. It is used with other herbs in the treatment of venereal affections, liver complaints and dropsy[].

Other Uses

A fibre is obtained from the leaves, a substitute for hemp[]. It is used for rope and coarse cloth[]. Also used in thatching and basket making[].
The root is long and fibrous, it is used for making brooms, brushes etc[].

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 in early spring or early autumn. 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.