I have a neighbor who wraps the aluminum sheet around is pecan tree trunk, and then just duct tapes it tight. Only put the duct tape long the top and bottom edge in order not to give the squirrel a tape path to climb. You could get fancier with other kinds of clips. You don't need nails.

Of course, if you don't mind small perforations in the bark, just use a staple gun.

have you seen the web video mission impossible squirrel?
good luck, I've heard the metal works.

Here it is!

Here is a link that might be useful: Mission Impossible Squirrel ...

That's funny. And scary. I think my pecan tree may be doomed. But I did make a baffle based on one I saw on you tube one time. I wrapped a foam "collar" around the top of the truck and hung a metal vent pipe over that so it wobbles when it's touched. I haven't seen a squirrel in there since I made it, but I'd like to set up my wildlife camera to see if they are sneaking by me.

I understand they do not like thorns but I do not see how you can grow a rose bush against any tree

Especially not a pecan tree that drops nuts on the ground. Another thing I'll have to deal with if I have any pecans left by then.

I've watched a squirrel nibble one rose bud after another...the rose had thorns. They navigate bougainvilea easily as well.

Where food is concerned...nature finds a way
cheers
c

Also, I assume each tree you want to protect is far away from any other tree? My squirrels never hit the ground. They just go from tree to tree to tree via branches. They have no need for most of the tree trunks.

So far, our tree isn't near enough to another tree. But it's not very big yet either.

Well, the baffle seem to be working, but now the stinkin' squirrels are jumping from the ground until they can grab onto a limb! I put pool skimmers under the lower limbs to hold them up higher but I doubt that will stop them for long.

The crows have also been working on the tree too.