Space between bluebird boxes?

[Lady19thC]

I am hoping someone can give me advice to how many feet apart I should place my bluebird boxes. I have two. One place said to put them 20 feet apart, and another said no more than 9 feet apart. I am hoping to attract tree swallows and bluebirds. Had tree swallows, last year, with 4 eggs, but house sparrows attacked the nest and destroyed them before they were even hatched. So, any advice would be appreciated. Thank you!

[birdpotter]

I have read 300 feet apart, if you have enough space and enough boxes.
If you can get a couple more and just put them in different spots, just to see what the birds prefer, that would be a worthwhile purchase. I had five spread out and got two pairs of Bluebirds, a flying squirrel and a pair of House Sparrows, who chose the one closest to my house and I don't think they were ever successful. The one box the bluebirds prefered the most was in an odd place. It was on the corner at the top of my four foot chain link fence. I think the combination of it facing an open field(there was a immediate dip from the fence giving the box at least another foot from the ground) with one small tree close by for the fledglings and the fact that my dogs kept away the predators from the other side of the fence made it an ideal spot.

So good luck and keep us informed and in photos of your birds' progress.

Elizabeth