I have them happily spreading in my zone 3 garden, so they should survive for you. My problem is that they don't always bloom. It always depends on the type and duration of spring we get in Calgary. Some years, we go straight from winter to summer!! Last year, we had a long spring and I had lots of flowers. You'll be surprised at the treasures you can grow in zone 4. Welcome to the Great White North!

Oh my! They not only survive, they multiply, quickly, by seed. They reseed all over the place, preferring shady areas. I love them. My book says they make a good salad too, with more vit A than spinach.

I got a few very tiny plants last spring from my neighbours yard and by the middle of November I had to divide them and move them around, now I have about 10 nice plants about 8" round all madly blooming. I may have to try them in salad, they way they are growing I think we'll have to to keep up with them!

They come in lots of lovely varieties too! My darn husband doesn't like them as they spread quite readily, but I just love them. Wisconsin state flower too!