There is a lady on the Cottage Garden Forum who has great luck with the Mason Bee houses. She lives in California, but she may have some tips. If you search that forum, the thread would be by Danceswithwolves.

Cameron

If you have blooming plants outside, you'll bring in Mason or Orchard bees. It may take a while for them to discover your bee house. There are native types in this area so there is no need to import any from another state, just encourage the wild ones. I haven't seen any so far this year, but I have seen plenty of honeybees. Keep in mind that most of the Mason and Orchard bees are tiny, the size of a housefly. Also keep in mind that you will eventually have to manage them and their bee house. The mite infestations get so bad after a year or so that you'll need to clean the cocoons while they sleep through the winter to get rid of them. Otherwise the mites and pests weaken the bees and your house will be empty.

I see a Mason bee house in the current catalogue for Gardener's Supply Company.
Trouble is (and I appreciate being told)the company said this house would only last 1-2 years.
It consists of bamboo tubes wrapped in what looks like wicker/woven grass and you hang it from a tree.
We have wild bamboo in the back forest,providing smaller tubes up to a 3/4" hole.
If I thought I could get carpenter bees to use it I surely would try but they are territorial rather than communal.
You could look online at wwwdotgardenersdotcom. The mason bee house was 14.95 but it looks pretty easy to make.

Here are some instructions from the NWF to make your own Mason Bee house. :)

Here is a link that might be useful: How to make a (Mason) bee house

I am here in the Piedmont. I am on my third year of putting out a home-made bee block for Orchard bees. They have been very successful in getting bees to nest and leave larvae. There seem to be many types of "Systems" being developed. They all seem to work to some degree. Go with the one that fits your pocketbook and maintainece style.

I will say that is is a lot of fun just to sit and watch the bees fly in and out for the next couple of months.

If you search under my name you will find several postings about the topic and a link to a photobucket album with my Bee blocks. Let me know if you have any questions.

Here is a link that might be useful: Bee Block photos

I live near Raleigh and have put out a Mason Bee house for several years to assist with my blooming trees. I bought the first batch of larvae and have seen a steady increase in my livestock, so I must have enough work for them! I purchased the original stock and house from Karen at Pollinator Paradise. I still get my straws from them. They make cleaning up at the end of the season a snap.

Here is a link that might be useful: Pollinator Paradise

Thanks for all the information. Will definately check the site. I bought the houses from gardeners supply house. one for me and one for FIL. He's a master gardener, boy am i lucky to have him!! We are hoping for wild ones to fly in and I have seen lots of honey bees lately and have a house of carpenter bees. Last year gardening was so bad no squash or cukes or beans would grow - am hoping for better success this year and a little different going out to the yard. My boxes are built and I am fixing to get my "Mel's Mix" together and put in the boxes and grow grow grow! Thanks again for the replies and happy gardening all!

I rarely noticed mason bees before until last week when we were building a tool shed connected to our brick house. No sooner did we get the framing up and the mason bees tried to enter every knot (knots are darker and look like holes) in the lumber.
They investigated the weep holes in the brick walls which are just the right size but apparently previously used so unsuitable.
Guess that's why Gardener's Supply probably said that house I described and you bought was only good for one or two years.