I planted sweet potato slips back at the beginning of May. I got the slips from my good gardening buddy Bill. Before I planted them, I spread a few wheelbarrow-fulls of trash wood mulch from the dump.
The sweet potatoes sprawled all summer, getting a bit bug-eaten but otherwise carefree and pretty enough in their own way.
I decided today was the day to harvest -- some of them were huge, some of them needed another month. I harvested about ten pounds in the, maybe, ten by ten area where I let them run wild.