Tough socks?

This is absurd, but it seems every pair of socks I've purchased in the last year are cr*p, no matter how much or how little I spend on them. They've all developed holes within a few uses. They fare worse on the farm when wearing gumboots or other footwear liable to get dirt in em. So, this feels like a stupid question - but has anyone got any memory for socks they've bought that have lasted a good length of time? I'm lucky in that I don't blister, so not too worried about any of those "features" Would prefer wool or other natural materials, but main criteria is toughness (which usually negates wool). Any tips?