Dutch irises are mostly hybrids that came from crossing Spanish bulbous irises with other iris species. They are a popular garden favourite particularly in cooler areas where other irises might have trouble during the coldest months.
Dutch irises have long narrow green leaves that stand erect to about 2 feet tall. They have bulbous roots rather than rhizomes like many other irises.
The flowers are typically iris shaped with both bearded and standard flowers. They flower in spring with colours ranging from light to dark blue, purple, yellow and white.
They prefer full sun to part shade in USDA zones 6 through 9. Bulbs should be planted in moist well drained soil 6 inches deep during the fall.
Dutch irises do not need to be divided as often as irises with rhizomes. Dig them in the late summer or early fall and replant with other fall bulbs.
Dutch irises are popular cut flowers in the florist trade. For landscapes they make good borders and dwarf Dutch irises are used in rock gardens.