Anyone want to take a guess? Tossed all types of stone fruit in this location.

Prunus virginiana

Would Jeffrey have been eating the fruit of that species and throwing the stones about?

If you carefully excavate at the root what kind of stone do you find? And what are the dimensions of those leaves?

Did you toss an avocado pit in there?

https://www.google.com/search?q=avocado+leaf+identification&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjewNTs6rzcAhURc98KHR1KABMQ_AUICigB&biw=1455&bih=694

I’m in Ontario Canada so not an avocado!

Do you think it could be a cherry plum??

It does look as if it's from the cherry family

You don't need to dig it up. Just remove a little soil with your finger. The stone won't be far down.

The OP referred to this as a stone fruit. My understanding of that was that this was a fruit s/he has eaten and discarded the pit. Is that a correct assumption? Would that be something you'd do with P virginia? It's clearly a Prunus of some sort.

btw Jeffrey, I've had both dates and avocados sprout in my garden and our summers are much colder than yours. Of course they don't survive the winter.