My problem is that I am in the south and you are in the upper Midwest and Northeast. I only know what has worked for me but I am a hobbyist grower, not a commercial farmer. My garlic grow tops in the fall and those top persist, though grow little, during the winter months. I wish I could tell you the best time to plant garlic in your areas, but I simply can't. I have no experience outside the south. I would think your Extension Service could figure that out for you.
Two years ago I had lots of scapes. I don't know what the percentage of scape production was. It was not important to me. Last year I cut all the scapes off as they formed. This year, with so few scapes evident, I just let them grow.
