I find that many of them separate easily after the stress of our very wet winters.
Trixi also posted on face book that spring is not the best time to divide and sell heuffs, because some of them in the colony will bloom. She also explains how to identify some of them that will bloom. Very informative.
Dividing to late in the year can be difficult because they are starting to slow down and go into winter dormancy.
I like the idea of dividing in the spring, so they have plenty of growing time before the next winter hits. I do agree with Trixi that you may not want to sell or trade them until later in the summer. By then you will know for certain which ones will bloom.
