Iris × pseudata (hybrids between Iris pseudacorus and Iris ensata) are part of an elegant and relatively new group of irises with striking ornamental value.

Gardeners seeking something unusual may want to discover Iris × pseudata, a captivating hybrid born from the union of two distinct species: the robust and water-loving yellow flag (Iris pseudacorus) and the refined Japanese iris (Iris ensata). The result is a unique group of hybrids that combine the vigorous growth and adaptability of pseudacorus with the elegant floral form and exotic coloring of ensata.

These irises typically bloom in late spring to early summer, bridging the gap between bearded irises and daylilies. They are in bloom now in late June. The flowers often display intriguing veining, soft yellow tones, and even bluish or violet highlights—often with a dramatic signal patch reminiscent of their wild parentage.

Another ornamental asset of Iris × pseudata is its tall, sword-like foliage, which grows in elegant vertical fans. In spring, the emerging leaves show a striking two-tone effect: a pale lime green midrib is framed by deeper green margins, giving the plants a luminous quality when backlit by the sun. This effect adds interest well before the flowers appear and continues to provide structure and contrast through summer.

Despite their exotic looks, Iris × pseudata are hardy and quite easy to grow. They prefer moist to wet soils and are ideal for rain gardens or the edges of ponds, but also perform well in regular garden beds with sun to part shade and occasional watering. They benefit from division every 3-4 years to maintain vigor and prevent overcrowding.

Japanese breeders have led the way in developing cultivars like ‘Yarai’ and ‘Kinshu’ with refined floral traits and controlled vigor. In North America and Europe, they’re still underused, but those who grow them often become instant fans. I know I have!

I acquired ‘Yarai’ (also found in garden centers under the name ‘Night Thunder’) in 2023. It stands out with its truly unusual coloration. The falls are a soft yellow, lightly veined and speckled with wine red, which together create an overall orange impression. The standards are a richer wine red, and the signal is a bold, deep yellow. What a striking iris! The plant is tall and vigorous, so much so that I’ve already lifted a side shoot and started a new clump in another border.

Alongside ‘Yarai’, I planted ‘Tsukiyono’ last year, often sold as ‘Moonlit Field’, again a direct translation of its Japanese name. Bred by Hiroshi Shimizu and registered by Carol Warner in 2005, it is classified as midseason. So far this spring, the plant was still shorter than its expected mature height of 44″ (112 cm). The standards are creamy white with a delicate lavender edge, while the falls are softly veined in lavender. The bright lemon-yellow signal is adorned with a dramatic dark purple eyelash pattern, an elegant contrast to the overall gentle tones.

My newest addition is the unregistered ‘Cat’s Eye’, which I discovered during a visit to one of my favorite nurseriesin the spring. Reminiscent of ‘Tsukiyono’, it features even whiter falls accented by the same distinctive dark eyelash pattern, hence its evocative name. It likely benefited from greenhouse cultivation earlier in the season as it bloomed in May.

While Iris × pseudata inherits the strong growth and adaptability of Iris pseudacorus, it does not share its invasive nature. Unlike yellow flag iris, which spreads aggressively by rhizomes and seed, sometimes escaping cultivation and disrupting native wetlands, Iris × pseudata remains clump-forming and well-behaved in garden settings. This makes it a much safer choice for gardeners who want bold foliage and exotic blooms without risking the takeover of surrounding plantings or nearby natural areas.

To learn more:

Pseudatas, by the American Iris Society