My slips were from the local farm supply (this URL unlikely to last more than six months). I had chosen scarlet (a pure purple) and NC-122. NC-122 seemed more vigorous, and it certainly sent out many vines. But scarlet produced the most sizable tubers, the largest of which i stabbed with the digging fork. Just like with potatoes, i do wonder how many i might have missed. Perhaps some of the tubers -- particularly the little stringy ones -- will over-winter and sprout next year.
It was an excellent ground cover. Pity the deer adored the vines, nibbling any that made it to the fence. The vines seemed to keep the stilt grass down in the area where the plants started early. There were some areas where the vines extended into that seemed pretty stilt grass rich.
I will try and keep one or two of the smaller purple potatoes as mother plants for next year's slips. I can imagine them doing well around the base of okra. I won't have the conflict i had this year, of waiting for potatoes to be done, so i will have more room to plant. And i'm comfortable with making my own slips.
I did find a crookneck squash had finally set fruit just before the freeze.
I'll be fertilizing next year. I suspect the low output of the garden due to weather patterns that delayed the start of the growing season. While we had a very warm winter 2019-2020, and March was extremely warm, May and June were unusually cool. I think the warm March affected my little plot even more by bringing an early green up in the trees, which shaded the ground, compounding the cool spring. Everything seemed to take forever to get started this year.
So for 2021 i have a number of plans: create a lightweight fencing around the driveway island (that is likely the warmest and sunniest place in the yard). Plant tomatoes, peppers, basils, and marigolds there (nothing particularly attractive to deer or rabbits). No solanaceae in the fenced garden plot, which means no potatoes next year. Apply the feather meal for nitrogen and the other supplements. Cucumbers worked this year with no significant powdery mildew, so try cucurbits again.
Anyhow, now i need to figure out what to do with the sweet potatoes. I'm not sure i can "cure" the giant purple ones i stabbed.