Here’s what I do: Buy a sweet potato at the grocery store, dig a shallow hole somewhere in the yard, and bury the tuber. Then I forget about it. I don’t even remember exactly where I buried it. It doesn’t matter. In the spring it will send up a bunch of little vines and I’ll say, Oh yeah, I buried a sweet potato there.
The other day I bought the sweet potato in the photo above and buried it at the edge of the canopy of my orange tree. I also buried a purple sweet potato near there that I had grown last year so I can grow more next year.
What I’ll do next spring is use the little vines that the sweet potatoes shoot up in order to grow additional sweet potato plants through the summer. It’s ridiculously easy. Essentially, you clip off a section of vine about as long as your forearm and stick it in the ground. (Here’s a short video showing how to plant sweet potato “slips.”) Give them water through the summer. Come fall — voila! — you’ll be digging up sweet potatoes that look like the one you buried last fall (now).
So if you want to grow some sweet potatoes next summer, pick up a tuber next time you’re at the grocery store and bury it.