Hi' Henry in Mi, I was going to wait till the tree was fully grown and then look for Dave's e-mail, asking about Willow roots and what they can do to walls, and how can you repair cracks in walls and foundations.some info about willows. 1)the roots are two time the hight of the tree: 6m high tree then the roots are 12m long,they love water, and will suck life out of any other trees that are close. nice talking to you. John 2000