Answer: Daylilies can be divided nearly any time however the preferred time is probably late summer after they have finished blooming for the season. Larger divisions will result in larger better blooming clumps faster but you can divide them as small as just one or two fans. Tall bearded iris are usually split or divided in late summer (July and August) also. This allows them time to become well rooted before seasonal freeze/thaw activity and winter cold sets in.
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