Hi, from what I've read, Yukon Golds and Fingerlings are the type of potato that doesn't benefit that terribly much from repeated "heaping". Some varieties will grow more potatoes as you pile the dirt higher up the stem of the plant. Each set of leaves covered by dirt will produce most potatoes.

This may not be the case with Yukons and Fingerlings, but I could be wrong. It's worth a shot to at least fill till u reach the top of your boxes (which look very nice by the way), but I wouldn't go the extra mile heaping however. I also got some Yukons to plant and some reds myself. I read the reds do like the heaping, so we shall see. Good luck! Sorry I can't be of more help!

Awesome towers....I used the potato bags myself last year (store bought greens ones made for potatoes) and think they did better than the ones I had in the ground. So this year I'll be using them again, in addition to several other types Ive seen (chicken feed bags, soil bags, trash cans, ....Yep they work a friend used her feed bags last year with GREAT success). Please keep us up to date with info or pics on your potato towers ill be following...oh and GL =)