I planted Yukon Gold around late March/early April. I started them in 3 grow bags and a tall homemade "barrel" made from plastic poultry fence. The ones in the grow bags sprouted pretty quickly. These are the ones that have generally died back. I went ahead and grabbed the bag that looked the worse (about 90% dead) and went digging for potatoes to see what I'd get. I got 3 large, fully developed potatoes, 2 small-to-medium potatoes, 2 tiny pearl potatoes, and 1 smashed one. I haven't harvested anything from the other 2 grow bags yet.
As for the poultry fence "barrel," these sprouted many weeks after the grow bags. Not sure why it took them so long but they are still trucking right along in their full green, lush, flowering glory. Depending on how these ultimately turn out, I may use this method permanently moving forward. I didn't use ANY soil with these potatoes.... Instead, I used 85% dead leaves and 15% compost.