I planted a December apple tree in my garden last year. It's still an apple stick, but I'm hoping for fruit in a year or so. The breed is supposed to be very old. And it is supposed to fruit in December. It's also supposed to produce good cider apples. If it works (pun intended.) I'll let you know.
By the way, I like the carol, and will think about it, when I look out at my apple stick, soon to be a tree.