I love the history of Bottle Trees and colored glass always makes me happy. And it can't hurt to ward off an evil spirit or two.
Here and
here are some interesting websites with lots of pictures on the subject . And here is our blue bottle tree.

All these bottles came from all the many washed-out essential oil leftovers. So now our nectarine is extra beautiful, has good juju AND smells faintly of patchouli, vetiver, frankincense and rose. It's just starting to bud too!