Answer: This is a good time, in early spring. You can also do it in late summer with very good results. Dig up the clump taking as much root as possible, then cut straight down between the shoots to separate the plant into sections, each with a top and some root. A section about six inches across will make a very nice plant this season. You can divide it down to individual "fans" but one fan can take a few years to look like much in the garden.
Make sure to replant them promptly and water them well until they become reestablished just as you would for any new plant.
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