Iris ensata Dinner Plate Tub Tim Grob - Japanese Water Iris

Iris ensata 'Dinner Plate Tub Tim Grob' is a magnificent Japanese water iris that produces flat and double flowers, particularly wide, of a delicate pastel pink. It is a mid-season variety that blooms in summer, between June and July. Unlike our garden irises, this rhizomatous perennial is comfortable in non-limestone 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 (synonymous with kaempferi), hanashōbu in Japanese, better 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, more precisely to the wetlands of 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 growth and flowering period, but appreciate slightly less moist soils in winter: in nature, they are found above the water level, which often drops in winter and then rises again in spring with the melting of snow.

The 'Dinner Plate Tub Tim Grob' cultivar is a recent horticultural creation from the 'Dinner Plate' series, which brings together varieties with oversized and remarkably coloured flowers. This variety forms an erect, rather upright tuft of vegetation, composed of fine leaves. The plant will reach approximately 60cm (24in) in height when in flower and 50cm (20in) in width. This iris slowly spreads on the ground through its rhizomes, becoming more beautiful year after year. The deciduous foliage is medium green and composed of long, slender, sheathing leaves with 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 one bears 2 to 3 very large flat flowers measuring 15cm (6in) in diameter. Each flower is composed of 6 large, flat, undulate sepals, topped with 3 slightly smaller petals and 3 erect styles. The petals and sepals are a pale lavender pink, finely veined with a deeper purple-pink, while the styles are pale yellow infused with pink. Bright yellow signals illuminate the entire flower in the centre.

Often cultivated on the banks of ponds and basins, Iris ensata, like many marsh plants, can live with their "feet" in 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, enriched 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 Tub Tim Grob' with other "Dinner Plate" varieties, Anemone rivularis, Darmera peltata, Lobelia 'Queen Victoria', Astilbes, Lysimachias, and Ligularias, for example.