How to prevent trees I(I don't know what it is) from producing berries
A few years ago a weed started growing in the corner of my back yard. It threatened to over-grow and destroy a treasured rose bush. We did everything to contain it, including cutting it back and down, and removing the rosebush to another location. t continued to thrive (the weed) and now is a flowering tree which is quite tall and has taken over half of my back yard creating lots of shade and a lot of dark berries king of the color of black berries and they are sweet. They are messy and drop continuously on my new patio stones and leave a dark purplest stain.
I don't know where it came from, and the only positive thing is the shade but it doesn't allow anything else to grow. I don't want to cut it down but can I stop the berries"