When I was a kid, I always had holes in the heels of my socks. My mother would stitch them up (not proper darning, because it was a lost cause), and then later I tried dealing with it myself. I tried darning, but on the thin cotton socks of childhood, it was just too tedious. I eventually hit on the cheating method of putting tape over the holes, but you can imagine how well that worked.
I’ve looked at pictures of old socks from museum archives, and the heels are always ratty. It’s what you’d expect—that’s where friction is most likely to happen. Today, we knitters strand a little nylon yarn into the heels, or maybe sewing thread. If we are spinners, we make the heel yarn especially well twisted so it won’t pill and shred. Some old sock patterns are drafted in such a way that you can easily replace the heel, the toe, or the whole under-foot of the sock.
The cleverest of these methods, to my mind, is the one Elizabeth Zimmermann called the “afterthought” heel. It’s routinely used on socks from the Middle East, as well as on the kind of industrial work socks that you make sock monkeys from. Here’s how it works: Simply knit a tube sock from top to toe, but at the point you want the heel to turn, knit in some waste yarn on a number of stitches equal to half the total number of stitches in the round. For example, if the sock is 72 stitches around, knit 36 stitches in waste yarn where you want the heel turn to fall.
When your tube sock is finished, go back and slide a double-pointed needle into the 36 stitches that are above the waste yarn, and another double-pointed needle into the 36 stitches right on the waste yarn. Pick out the waste yarn. Lo, you have a yawping hole where the heel will be. Put half the stitches on each double-pointed needle onto another double-pointed needle. Can you see it? Now you have four double-pointed needles arranged in a circle, each with 18 stitches. Proceed to knit a few rounds on these four, and then decrease as if you were shaping a toe. You end up with a rounded heel sticking out the back of the stocking that matches the rounded toe on the end of it.
When that heel wears out, you can just ravel it back to the leg of the stocking and do it all over again. You can find more precise instructions for this in the Ukrainian Sock in Nancy Bush’s newly revised Folk Socks or in my own Sock Monkey Sock in Christmas Stockings. A cool thing about this method is that, once you’ve knit the tube sock, which is pretty mindless work, you can decide to just go with it and forget the heel. Not that I’m recommending it.