Where can I find or buy Minnesota walnut seeds?
Thank you for the question. I don't know of a specific source for Minnesota walnut seed, but it might be a simple as knowing someone with a walnut tree and asking them if you can have a few nuts! During my research on your question, I learned that planting walnut trees from seedlings is generally more successful that planting directly from seed due to predation risk from squirrels or other rodents. However, there are directions in this University of Minnesota Extension publication on how to plant walnuts seeds in a way that reduces predation risk: http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/growing-black-walnut/
You may be able to find some resources to email or call in the University's department of Forestry that could direct you toward specific Minnesota grown walnut seed http://www.extension.umn.edu/environment/trees-woodlands/
If you decide to plant seedlings, the Minnesota DNR Forestry division sells seedlings in bulk for reasonable rates. Here is their link: http://www.dnr.state.mn.us/forestry/nursery/index.html
I'm sorry I couldn't tell you where to get seed but I hope these resources result in you being able to find what you want. Thank you for contacting Extension.