I am following this thread with interest as I bought a small sack of alfalfa seeds recently from OSC, and will be growing it for the first time. While OSC indicated that the seeds are non-GMO it would appear that alfalfa readily cross-pollinates and could easily become contaminated-- but here in the suburbs I would be very surprised if anyone else was growing alfalfa, making a cross unlikely. My neighbours and I are working on a project to restore a very steep slope that is eroding and becoming a noxious weed haven. The hope is that planting a few rows of alfalfa across the hill might help to stabilize the bank, while improving the soil at the same time. From what I have read the roots of alfalfa can go down 5' deep. It would be great if it thrives, so we could cut it for home grown mulch too.