I have read the very old thread at root system on Yucca Rostrada, and I am also curious about planting near a retaining wall. I see it shouldn't be an issue but now I have concerns about the weeping blooming cherry that is planted between my home and the neighbors. I forget whether it is a dwarf or not but I believe it said 15 to 20ft span which is about how far the houses are spaced. Will this be an issue for my old fieldstone and granite foundation? And if so why do I see so many of these trees planted infront of homes?