I'm pretty sure you'll have to dig them in the fall and replant in early spring.

Dutch iris are perennial to zone 5. I did read on this forum recently that they decline after a few years so you have to replant. That hasn't been so for me. I was thinking earlier this spring that mine might need to be divided, they seem to be quite thick. My blue ones have certainly returned dependably for at least 4 years. I planted a package of yellow ones about 4 years ago, this year I counted 6.

I've had mixed results with Dutch Iris coming back. In my heavy soil, they have only come back where they are planted on a slope--and even there, not vigorously. I did hear that they need excellent drainage. How is your soil, cassieinmass?

Anyone else have advice on these beauties? They bloom in the gap between the tulips and the perennials, plus they are so lovely. I once had orange oriental poppies, Alaska shasta daisies, and blue Dutch Iris blooming together. It was a stunning combination, but the iris didn't come back in that spot.

hepatica