I'll list you some perennials
Monkshod
Ajuga
Ladys Mantle
Japenese Anemone
wild colombine
jack in the pulpit
goatsbeard
wild ginger
hardy astilbe
Heart leaf bergenia
pink turtle head
green& gold goldstar
bug bane
lilly of the valley
Corydalis
bleeding heart
foxglove
barrenwort
sweet woodriff
Lenten
rose/hellaborus
coralbells
hosta
crested iris
siberean iris
rocket ligularia
dead nettle
lilirope grass
cardinal
flowerjapanese anemone
woodland phlox
solomons seal
japenese primerose
bethlaham sage
foam
flowertoad lilly
snow trillium
periwrinkle
Annuals
Flossflower
begonia
amethyst
flowercloes
polka dot plant
impatiens(good choice)
Lobelia
nicotina(green one)
wishbone
flower GRASSES
gold variegtated Hakone grass
Ribbon grass(I'd LOVE some)
Ferns
Maidenhair fern
lady fern
japenese painted fern
hay scented fern
ostrich fern
cinnamon fern
royal fern(wow hardy to
zone 2!)
christmas fern
Bulbs
I just love claduims,but they are a PITA to dig up yearly.I did have a nice shade bed once that was claduims/ferns/EEtarro/cloeus/vinca/daffs.The weather took the claduims cause I didn't dig to store,ducks ate my ferns.But it was a GREAT look.I've thought I might buy claduims again,but keep in pots and sink pots in the shade bed.
Claduims
autuam crocus
snowdrops
spanish bluebells
squill
Well THIS should keep you busy.I tried to stay within your
zone.Accept for claduims.