When and how do you divide peonies and irises?
Now that irises are out of bloom and look miserable would be a good time; make sure that you re-plant them at the same soil level they were at originally and so the sun hits the corms of the irises. I usually transplant peonies after they are out of bloom but a bit later in the season; you have to be careful that you don't plant them too deep - make sure that the eyes are at the same level in the soil they were before. In both cases, just whack them in half or in four with the sharp part of a shovel. Make sure you have a nice well-developed hole the same depth as the root system of each plant. Add lots of compost to the top of the soil after watering deeply and do it on a cloudy day.
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