I just put an order for fall bulbs, among which I have some nice crocus (croci?). I am wondering if I can plant them in my window boxes instead of the ground since the backyard is of little interest in early spring. I thought it will look beautifully in the front of the house when spring hits, but I am concerned of the freezing. Will they stand the harsh winter, or do I need the protection from earth?

I am in zone 5B

Thanks