Hey Jen4, I live in a trailer park, got one of the better spots next to a field, never the less I still have a small yard. My two boxes are only 16 ft apart, that's probably inside the recommended distance you should put them next to each other but if they take to them who cares. I'll just try to place the next new one where they can't miss it when exiting the present one.
Keith
{{!gwi}}

Congrats on the fledglings Jen! As far as nestbox placement, bluebird won't nest any closer than 300 feet apart however you can get TRES and Blues closer together than that. I would say about 20ft apart if you want TRES and Blues together but no further or you could get two sets of TRES. I have two sets of paired nestboxes at a park where I monitor 5 boxes, the paired ones are 15ft apart. So far (this is the second year) we have only had nestings in one of each of the paired boxes. Not sure if they are too close for comfort to get both TRES and Blues together or not. At my house we added more nestboxes. We have two paired 18ft apart and have TRES in one, the other the Blues were going to take but then they discovered one they liked a bit better a little further away. Then we have another pair of boxes on the other side of the yard, they are like 30 ft apart (meant to put them more like 20) and they both have TRES in them. Then we have three boxes along the back of our property facing an open field. They are about 90 feet apart and they all have TRES in them. Good luck!! Hope your second brood of Blues fledge fine too!!

Keith, I still think you should get those birdhouses off the wooden posts, if nothing else at least put a baffle on them. You have been lucky so far, I would hate for that to change.

Donna