Well, ya can use a shotgun if yer a good eye and use a slug but that still maims the tree. If yer a piss poor shot and ya use shot, yer definitely gonna maim the tree. I'd say... DON'T SHOOT THE TREE. WTF did the tree ever do to you?

If I HAD to shoot mistletoe out of a tree I would use a 22... a course, that takes marksmanship... a tha loikes a yer Rap. I spect Rap could knock mistletoe outta yer trees from Idaho dependin on tha wind. Jus ask im. But, ta be safe, take cover eh?