Northern VA here 7a, I have locked in on Halloween as my prime time. I've done a week or two earlier and a week or two later, all have the same results. Personally I find harvest times to be much more important than planting times.

Agreed. I planted garlic in central NJ for many years and experimented between mid-October and mid-November with equal results, and settled on first week of November. The goal is to allow about six weeks of root growth before the ground freezes with minimal top growth, but there is plenty of flexibility.

I now live in southwest Virginia with the same climate (zone) as central NJ because of the higher altitude (2600 ft). Again first of November works well here.

Interestingly, one year in NJ I had a little space left in my garden and decided to plant more garlic. I planted on December 11th and this garlic outperformed the rest of the crop planted earlier. Go figure - it's a pretty hearty vegetable!

TomNJ/VA