Stop the killing.

I moved into my current home about 18 months ago. My rear property line is shared with my backyard neighbor. He's planted four pine (or pine-like) trees along the property line, presumably for privacy purposes years down the road.

Or rather, he's trying to plant them. The land between our streets, from one end of the block to the other, is sloped towards the property line for drainage purposes. Without fail, he has to replace at least two of them by the end of the summer, and at least two of them in the spring, because they spend a lot of time sitting in water. As you can see, coming into March and after a significant thaw in the last few weeks, tree #1 and tree #4 seem to be leading the race.

So do neighbors like this ever get less dumb? Or is he going to continue killing 4-6 trees per year ad infinitum? And will it ever stop being funny to me? This is my first adult venture into the 'burbs, so this is all new to me.