After Iris Blooms, What Needs To Happen

Question

When to thin, when to cut back

Answer 1

After irises have finished blooming, you can remove the bloom stalks. Then leave them to replenish till late summer, when the plants go dormant. Then, if crowded, you can dig the clumps and divide the iris. These articles should help:

https://www.gardeningknowhow.com/ornamental/bulbs/iris/divide-bearded-irises.htm

https://www.gardeningknowhow.com/ornamental/bulbs/iris