"George.com" wrote in message

I dug up the dead lot & got a few spuds. This last lot came down with
something as the potato stems had started to rot in the compost. The stack
went in mid october so about 2 1/2 months. Heaps of top growth, 6 tyres
high, but bugger all potatos. I'll see how the other 3 tyre stacks go.

Sounds like your growing medium was too rich - all show, no go.