After the harsh winter, our eight bluebird houses were in dire need of attention before the arrival of their house guests. Dick removed them from their pole mounts and replaced the board roof on four of them. Next it was my job to scrape and sand peeling paint, apply primer, then a final coat of paint. You can put linseed oil on the bare wood or you can paint the houses as long as you choose a light color. I found what I think is a perfect color. It is paint brand Valspar in color "gray pine" J100-6A. We mounted them 6 ft. above the ground by pounding an 8 ft length of rebar two feet into the ground. Next we slipped a 6 ft. length of 1/2" diameter electrical conduit over the rebar. Then we secured the house to the pole with two 1/2" electrical conduit clamps.
This particular design is the "Peterson Bluebird House". It was developed by Dick and Vi Peterson of Brooklyn Park, Minnesota after experimenting with over 5,000 bluebird houses. The front opens easily for cleaning by pulling out the nail that you see on the side. The sloping roof discourages predation by cats. The Peterson's also built in features for insulation, ventilation, drainage, and ant control. For complete instructions on building these bluebird houses, contact the Minnesota Nongame Wildlife Program.
The houses are set up in pairs 25 ft. apart to minimize competition between bluebirds and tree swallows. Tree swallows are actually a good thing since they consume thousands, maybe millions, of flying insects. Pairs of houses are placed 100 yards apart. They should be in place by mid-March to early April, but if life has tossed you in a few too many directions, don't despair. Bluebirds will have as many as three broods during a season, although two is the norm, so just get them up as early as you can. You will be rewarded for your efforts when the first bluebirds arrive to take up residence and start their own little family.