I am so happy you consolidated bits of hard to find info/knowledge on spring garden favorites often grown in these mid-temperate zones and put them into one article! A great reference tool. I love to make up plant combinations and the early springtime is always such a challenge!
I do want to add that Bleeding Hearts (dicentra spectibilis) are a wonderful early perennial here in Zone 6. The old-fashioned rose colored kind are blooming right now with our white daffodils and it is a very pretty early garden combination.
And our Coral Bells (Heuchera) 'palace purple' are up and complementing our Hyacinth 'gypsy queen' very nicely.
Another: a few of our chartreuse euphorbias are up already complementing some very handsome yellow daffs.
And just one more: purple muscari 'Christmas Pearl' is a very early blooming variety and pairs well with daffs and early tulips and right now we have some blooming along with an early low growing hardy geranium (maybe it's "Max Frie"?).
So thanks again for your list. I can't wait to get to work on making up some new combinations! t.