This started growing out by the corner of the garage at a house I bought almost 3 years ago. I didn't plant any tree or even a plum pit, but it could have been carried by a squirrel from somewhere else and buried there; I find peanuts in the shell buried in houseplant pots I leave outside in the summer. I had a plum tree at my former that I couldn't bring with me when I moved (too large), so if this is a plum, I'd be happy.