umm i was speaking in the terms of benifitial purpose like when you plant a garden there are certian plants that will thrive better when placed next to each other. Whether its shade from a taller plant next to a small plant or deeper roots next to shorter roots etc. I was just wondering if anyone had any idea. EX Alder trees produce nitrogen so planting plants outdoors near alders would help (im not an expert could be wrong just example)