Cherry tree sucker
I just moved into a house. The neighbor has a huge cherry tree with a lot of fruit. I have a cherry tree as well that is sort of growing sideways from the fence where the neighbor's tree is. I have a feeling it is a sucker that was let go and is now a tree. It looks healthy and there is fruit on it but the cherries are the size of peas. If this tree grew from a sucker, is that the result and can I cut it down without hurting the neighbor's tree?
Your neighbor probably has a grafted tree, and the little tree is most likely a root sucker that has come up. The root stock was used because it is very hardy and strong, but it doesn't produce good fruit. It won't cause any problems to cut it down.