I had the SAME problem! I don't know why the hell they advertise these at 4' X 4'. Apparently they get more like 6' X 6'...even bigger. I guess if you prune them back hard to the ground every year (which they don't mind) it may get 4' X 4'. But if you want that sway look its better off left alone and pruned back hard every few years.

I made the mistake of moving 4 of them a few weeks ago. There top growth was so top heavy, and it was extremely hard to balance the shrub because of its ridiculous root structure. It barely had a ball it just had random 1" curvy roots. Yes 1" roots on a 1.5 year old shrub.

Moral of the story? Wait until leave drop. Prune lightly.
You can then prune back hard the following year.

Okay, thanks for sharing your experience with me whaas. Interesting about the small roots. The shrub is really much larger than I anticipated but also a lovely specimen. In my small front yard it overpowers every thing and looks ridiculous but it will be an asset in the back where it can sway freely.

You meant large roots right? A 1" caliper root on a 1.5 yr old planted #3 cnt. is out of control! lol

I know this post is from years ago and I shouldve read it before i attempted to move my willow just now. the size of the roots were insane and i couldn't quite move them all. the willow split in half and i'm thinking it's a matter of days before it dies. did yours survive?

Willows are tough; don't give up on it yet.

start your own post.. and add some pix of what is left ...ken

FYI When I bought my arctic willow the nursery had an 8 footer in their landscaping that they pointed out to everyone before they sold them to anyone expecting it to get a small cute willow.