Hi, You didn't say if you lived in northern Minnesota
zones 2&3 or southern
zone 4. There are a lot of shady plants. Some flowering plants for
zone 4 are Poker Primrose hieght 12-24 inches tall, Wood Poppy 18 inches tall. Some that are are hardy to
zone 3 and would be hardy to
zone 4 are the Astilbe's in Lavender, Pink,Red,White 14-18 inches tall,
Blue Columbine 24-36 inches tall and the red and white Bleeding Hearts. There are also so many textured plants that do well in your area. I myself thought I was doomed when the family tree grew bigger and bigger and my sunny garden became smaller and smaller, but I found some wonderful plants for the shade and I love them. Good luck with your shade garden, let me know how you make out.
Nanasgirl