Iris ensata is a group of moisture loving rhizomatous perennials. There are now many hybrids which are much showier than the basic Iris ensata types. They normally come under the 'beardless' Iris category.
The Iris ensata normally send up single stems from the rhizome - but sometimes branched stems. Each stem can bear 3 or even 4 individual flowers and as can be seen by the image, there are many choice - if not gaudy - varieties or cultivars.
Flowering period is normally mid summer - the image above was taken 23rd June. As distinct from the 'Bearded irises' this group like to have their rhizomes below ground level. As such, they respond well to mulching in the spring with a rich organic compost.
Iris ensata 'Sansation'.
The plants grow to 90cm tall, and are clump forming.
They can be planted at the edges of ponds or any damp moist soil situation.
Iris ensata - kaempferi - can be grown from seed. This can be collected from the plant in late summer and then planted in a sheltered place in containers - cover seeds with vermiculite. A cold frame or unheated greenhouse is ideal. Or, they can be collected and over-wintered in sealed container and kept in cool place until spring, when they can be sown and treated as above. Young plants normally take three years to flower.
But far better and easier, is to divide the flowered clumps in late summer and plant as required. Division of the old clumps should in any event be carried out every three or four years.
There has been continuing interest in this group of Irises, and the hybridists are continually searching for new ways to present this plant to us - as can be seen in the superb hybrid above.