Answer: Based on your description it is hard to make an exact diagnosis, but it is possible that onion maggots or onion thrips have caused the problem. Control measures include cleaning up and removing all garlic (and any other onion including the wild type) debris from the garden, rotating the planting location, and covering the plant with floating row cover to exclude the insects. The problem could also be due to weather--either very hot or very wet conditions, both of which can cause problems on their own and/or exacerbate disease. Finally, it could be due to the variety you are growing. Most grocery store garlic is grown in California, where climate conditions are quite different than in the east. The variety you've planted for the last 2 years may do well in California, but not be well adapted to your climate. I'd purchase some garlic from a seed company or nursery--look for varieties described as well-suited to your region.
Q&A Library Searching Tips