Planting Irises

(Question)

I have irises in my garden that are overgrown and surrounded with grass. Is it too late now to pull them up and replant them? If so, what is the best way to deal with them?

Thank you,
Janet Mannone

(Answer)

“Divide at the right time of year, after flowering, when irises become dormant during late summer, reducing the chance of bacterial soft rot. Avoid dividing during winter when irises are trying to survive on stored energy in their rhizomes”, Penn State Extension advises.

Irises do not like to be crowded at soil/rhizome level. And they like to be clear of other plants, especially grass. You may be able to tidy up the area as preparation for next spring’s division and transplanting.

Unlike most replanting, iris should be set firmly on the surface of the soil. Rhizomes need to be exposed.

..and remember to divide them again in 3-5 years. The gardener in the Kansas State YouTube video recommends yearly division and replanting, but that should not be necessary once you have done the major revising next spring. He clearly demonstrates the trimming away of foliage and the fanning out design of replanting.

https://www.youtube.com/watch?v=HhEjpI6L6Qc

https://www.ksre.k-state.edu/news/stories/2015/07/divide-iris072115.html

https://extension.psu.edu/dividing-irises