Iris ensata Dinner Plate Ice Cream - Japanese Water Iris

Iris ensata 'Dinner Plate Ice Cream' is a rather extraordinary Japanese water iris variety whose pastel flowers reach the size of a dinner plate. They are double, flat, undulate, silky, a very light lavender mauve, enhanced by small lemon yellow spots. It is a mid-season variety that usually blooms in July. Unlike our garden irises, this rhizomatous perennial is comfortable in non-calcareous and waterlogged soils in summer. Superb when planted en masse in wet areas and on the banks of water points, Iris ensata were once intensively cultivated in Japan, especially around Edo (the ancestor of Tokyo), for cut flowers.

Iris ensata (synonym kaempferi), hanashōbu in Japanese, also known as Japanese water iris, have nothing in common with our classic garden irises, except for their belonging to the Iridaceae family. The original Iris ensata is a fibrous rhizome plant native to Asia, specifically to wet areas in Japan, the Himalayas, and Siberia. These irises, known to be difficult to grow, like acidic and peaty soils (cannot tolerate excess limestone), are thirsty for water during their growing and flowering period, but appreciate slightly less humid soil in winter: in nature, they are found above the water level, which often drops in winter and rises again in spring with the melting snow.

The cultivar 'Dinner Plate Ice Cream' is a recent horticultural creation from the 'Dinner Plate' series, which brings together varieties with oversized and remarkably coloured flowers. This magnificent 'Ice Cream' variety forms an erect, rather upright clump of vegetation, composed of fine leaves. The plant will reach about 60cm (24in) in height when flowering with a spread of 50cm (20in). This iris slowly spreads on the ground through its rhizomes, beautifying year after year. The deciduous foliage, of medium green colour, consists of long and slender ribbon-like leaves, sheathing at the base, marked by a prominent central vein. The non-remontant flowering occurs in summer, more or less early depending on the climate. Flower stalks emerge from the clumps of leaves. Each stalk bears 2 to 3 very large flat flowers, 15cm (6in) in diameter. Each flower consists of 6 large flattened and horizontal sepals, undulated, topped with 3 slightly smaller petals and 3 erect styles. The petals and sepals are a pale bluish mauve, finely veined with a darker tone, almost white at the edges. In the centre of the flower, bright yellow signals illuminate the whole.

Often cultivated on the banks of ponds and basins, Iris ensata, like many marsh plants, can live with their "feet" in the water during summer, but their rhizomes do not tolerate being submerged during winter, especially if it is freezing. In our gardens, these Japanese irises will thrive in a loamy soil, well lightened with compost, but not drying out in summer. Plant them, for example, in heavy soil forming a slight depression, at the bottom of a slope, or on a bank where the soil becomes moist through capillarity. Combine Iris ensata 'Dinner Plate Ice Cream' with other "Dinner Plate" varieties, Anemone rivularis, Darmera peltata, Lobelia 'Queen Victoria', Astilbes, Lysimachias, and Ligularias, for example.