I want to keep the tree kind of short. I want it to look like a mushroom on top, then in the summer just trim the bottom.
Is this possible?
Gardening & Landscaping Stack Exchange is a question and answer site for gardeners and landscapers. It only takes a minute to sign up.Sign up to join this community
The comment by kevinsky is right on. Willows are fast growers, and even in our cool climate (Alberta) will do 3-4 feet a year. You would be constantly pruning.
You may be able to find a top graft, where a willow such as Dwarf Arctic Blue (S. purpurea 'nana') is grafted to a tree form trunk. This would reduce seriously the amount of top pruning required. But since it has full sized roots, I'd expect a lot of suckering.
There are many top grafted trees that may suit you better.
Look for a top grafted tri-colour willow. The top 'ball' will be about 5 feet across. they are usually centered 5-6 feet off the ground.