I have never actually hung one in a tree, but we have a large stand with 16 Martin gourds on it. They are free to swing and are full of Martin's every year.

Brandilyn

Oh.. I'd love to know the specifics of your martin gourds.

My Nannie (Grandmother) has had them for years now! Her's are plastic gourds, but they work the same way as real gourds. You are supposed to point the opening in a certain direction, but i can't exactly remember. I think it might be North West but you probably need to check on that before hanging them. What else do you need to know?