is to start with a chanin saw. As a very happy ex-owner of a willow tree, I would have to say that the day it was cut down was a very happy day. About the best thing that I can say about them is that they are not quite as bad as a box elder--but close.
Our city will not allow new planting of willows except the "Corkscrew" variety which are not as bad. Forget having grass. Think about how much money you will be spending to have your underground piping rooted out or replaced. The wood is so wet that 3 years later I still could not get it to burn in the fireplace and any other wood is ready in a year. Every windstorm, you get to go pick up pieces of your tree and your neighbors will really enjoy picking up after your tree also. Yes, I hate willows and so will you if you let them grow.