I need a potatoe, Harvest moon, animal parade!?

Ok, so I wanna marry the witch, but walking through her stupid forest everyday to gift her gets annoying, so, I want to give humphrey his vegetable pizza, bc i have already helped the elephant, and the giraffe. I have absolutely evrything except a potatoe, and I have just ped the Harvest festival in fall, hoping they would have a potatoe, but they do not, And also taylors seeds does not carry out of season seeds like in tree of tranquility. I really do not want to wait forever until winter!!! Please, where can I get a stupid potatoe?