A Permanent Potato Patch

I just happened upon this nutty thread so thought I'd give you an update.
The spuds grew well and I kept meaning to dig some up and see what they'd done. Then, one day, I went there and they'd all died off. Don't think it was blight, just got tired of waiting for me to do something.
The next plan is to leave them until next year and see whether they grow again.
(I'm trying to make this sound like that was what I'd intended to do all along )

The only thing that I do which resembles your permanent potato patch is my Jerusalem artichoke patch. I haven't checked to see if I am getting diminishing returns or not but they have been in the same spot for four years now?