I don’t. I do not care about potatoes.
Every now and then, you will see someone object to the presence of potatoes in a fantasy story. The argument goes that, because potatoes originate from South America, having them appear in a pseudo-Medieval, pseudo-European fantasy is an anachronism.
And I don’t care.
If you’re writing a secondary world fantasy based loosely on Medieval Europe, let’s be honest, you’re working with a lot of assumptions already. You’re assuming that somehow, on a world with a different geography, geology, climate, history, and pre-history, humans have not only managed to evolve but that they have evolved weapons, ways of living, customs, and diets that are similar to those that evolved here on Earth, in Europe.
That’s stretching credibility to an extreme. But it doesn’t end there. You’re assuming that, for the most part, the same plants and animals (plus some random fantasy ones) evolved also, again despite the differences in the world, even including perhaps the addition of magic.
How about birds? Birds are fucking crazy. How likely are birds?
As most people know, birds are dinosaurs. They are descendants of the very few, small species of dinosaur that survived the Cretaceous–Paleogene extinction event, when the giant asteroid smashed into Earth and wiped out most life, just like we’re descendants of the small mammals that survived. If the asteroid hadn’t hit, or if it had hit a different spot, no birds. No birds. Your fantasy novel requires an identical extinction event with identical effects if you want birds. That’s not happening.
That’s hardly the only example.
Your secondary world fantasy (and mine) makes no sense at all. It is based on a series of such unlikely coincidences and assumptions that it wouldn’t happen.
And, bearing all that in mind, you’re hung up about this fantasy world having potatoes in a European-modelled region rather than a South American-modelled region? Or the idea that, in that world, there might have been trade in potatoes between those equivalent regions a few hundred years earlier than happened on Earth?
So, no, I don’t care about potatoes in your fantasy. Put them in. Turn them into chips. Add ketchup. Why not?