Believe it or not, these spuds have been planted the recommended distance apart. With gardening you never stop learning. The more compost I add to the soil the better my harvests have been. I also added plenty of rock minerals before planting this year.
After that they have been ignored because of the amount of work I have had on. Previous years I have trailed hilling them with different material (straw-mulch-soil), did not make any difference. This year I just used the cheap bulk commercial compost, looks like it worked a treat.