Speedy,
Try checking with the UW Extension (
Tree & Shrub Selection | Wisconsin Horticulture ) Master gardeners well versed in local microclimates they may even be able to direct you to a member with trees for planting and definitely for care and under plantings. Near Milwaukee they have a perennial sale each spring from their own gardens. I have 2 black walnut trees and the only thing that has really lasted near them are bleeding hearts. Ferns and hosta lasted 5-7 years then started dying off and in the fall lots of stinky nuts.
They do grow somewhat quickly though and squirrels will help plant more.