Irises after stopped blooming

Question

I live in Central Oregon. I have several Irises in my garden. When they stopped blooming, how should I cut them, or not cut them. I do not store them in the winter. They always come back in the spring.
Do I fertilize them and when? And with what?

Answer 1

Iris require only division every 3 years or so. Without this, the tubers become crowded and fewer blooms are produced. Yearly addition of 1-2 inches of compost is all that is required for nutrition. If your soil is poor, a long-acting, balanced "flower" fertilizer may help. The large tuber that produced a bloom this year will never bloom again. These are discarded when dividing plants. Iris are one of the few plants that can be divided in late summer although choose a period of moderate weather, preferably cloudy. For now, prune out the flower stalk and let the leaves build up new tubers. When dividing, cut the leaves back to 6 inches tall and make sure each division has a fan of at least 3 leaves. https://www.gardeningknowhow.com/ornamental/bulbs/iris/iris-plant-care.htm

Answer 2

It is not necessary to cut them back. They are naturalized just about everywhere, and can survive unaided. This article will offer insight to get them looking their best: https://www.gardeningknowhow.com/ornamental/bulbs/iris/iris-plant-care.htm