We live in central Minnesota and tried to grow potatoes for the first time. They have been growing great and seemed to be generating an amazing harvest for us. About 1 month ago we started harvesting new potatoes and everything looked still perfect. Then slowly we started seeing some potatoes been chomped by little rodent teeth (just a guess based on the looks of the damage). This week I have been looking around the whole potato patch and it looks like now we have a potato disaster in our hands. Virtually every potato tuber has been chewed to some degree. Some entirely leaving just a little peel hanging form the vine, some have been eaten hollow leaving almost all the skin intact, and the rest of them have been eaten just from one side. We have not seen any unusually high number of rodents around - only a vole or two every now and then, but I never thought a couple of voles could do this kind of damage. I think we are talking about hundreds of pounds of lost potatoes.
Any ideas about what might have caused this? It is too late to do anything about this now, but we want to try to prevent this before next season.