I am myself quite slow to break dormancy most days, as Kevin can attest, so I'm glad they include this note, although I wish they'd include it more often. If a reader hadn't told me that buttonbush was slow, I would be starting to wonder.
Basically this means "Don't expect anything until after you've given up hope." Aesclepias--butterfly weed--is the worst for this. I have little hope of the one I planted last year returning, but I really really want one. (It's apparently easy to grow and starts easily from seed. You could not prove it by me. I have read all about the requirements and the dry feet and poor soil and whatnot, and I may just have to accept that it doesn't love me.) I got another one from Niche and am putting it in another place in the yard, in hopes that at least ONE will get the magic combination...but I won't know for awhile, because that one of course has not broken dormancy either.
And the other thing is that slow-to-break-dormancy doesn't always hold true. My chocolate snakeroot is supposed to be slow. Last year it was slow. This year it shot up as fast as anything else in the yard and is forming quite respectable clumps. (I planted three of them in the fall when I moved in--those and the hyssop are the oldest things I've planted. One of the hyssops didn't make it this year, but its buddy is coming back, and the snakeroot apparently finally decided that it's time to get down to business.)
Today I'll try to finish up the bump-out on the bed, which mostly just involves tilling the clay like crazy so I can mix it up with the bag 'o dirt. It's annoyingly cold out today, but digging will undoubtedly warm me up. I'm also gonna transfer a little of the bee balm--if it's spreading that vigorously, it can try standing up to the pineapple sage. And if it continues to go crazy like this, then next spring I'll transfer several clumps to the Deathbed and see how it likes life over THERE.