On Fri, 22 Aug 2014 15:53:11 -0500, George Shirley wrote:

[snip]
I have some untreated pine four by fours laying around and will probably
start boring the correct size holes in them this fall. Way to hot to
work in the garage or outside for that matter in August. Did that at our
old place and the carpenter and mason bees were always busy.

George

My dim recollection is that the holes should be 5 to 6" deep, else you get
too many males. Or perhaps you were going to drill sections of the 4x4s
lengthwise?