I'm going on my second year attempting to attract purple martins. The first year I had 6 gourds, and after the garden last year I now have 13. I removed a smaller tree, and trimmed other trees to open the area. Unfortunately we have many mature trees in excess of 50' tall. I've had the gourds at 10' and 15', and have played various Martin recordings attempting to attract them. The Amish have many martins within 5 miles of us, but I haven't seen one here yet. Currently the Martin gourds are about 100' away, where there's a more open spot by our bank barn about 150' away. We do have a decent sized back yard that's close to the house, but there's a couple power lines and a small pool. Any thoughts or suggestions I'd appreciate it. I want them for the garden, bit also to view for they're interesting birds. Thanks.