Sounds like you need some wood with holes drilled into it to provide a home for them. I took this off the web but I have never tried to do this to bring them to my plants.
http://www.ces.ncsu.edu/depts/ent/notes/Other/note109/note109.html

HOW TO RAISE AND MANAGE ORCHARD MASON BEES FOR THE HOME GARDEN
Stephen Bambara, Extension Entomologist
CAUTION: This information was developed for North Carolina and may not apply to other areas.

We had a huge swarm invade our wood pavilion here in Greenhead FL, its right above Panana CIty, unfortunately our home owners association assassinated the colony before I could stop them. It was eating the pavilion so I understand why :(

We had a solitary leaf cutter bee. It was pretty fun to watch him cutting away at the roses, rolling up a makeshift home.

Unfortunately, when they were done treating the foundation, our local termite team sprayed the remainder of their Termidor solution along on our fence line, without asking our permission. They rebranded the in situ dumping of excess chemicals as a pro bono mosquito treatment, to avoid the disposal costs. Environmental regulation at its finest.

We never saw the bee again.

. . . but that fence is all sorts of impervious to termites. It is a king among commoners.

Here's a link that I came across yesterday. I haven't checked many of the resources on the page, but there are many books/web links to choose from.

I listened to part of the discussion (video at the top of the page) and someone reported that they are using a lot of native/wild bees in California to pollinate almonds. Each native bee seems to pollinate much better than the honey bees that they have been using.

Here is a link that might be useful: The Ultimate Guide to Attracting Native Bees

I have my wood up and ready near my citrus trees. First year. I only had one cell plugged. Not sure what it is.
I do have a colony of digger bees that have been here at least two years.
After this cold weather, I am not sure I will have anything to pollinate.

I have a BUNCH of carpenter bees in my backyard shed.
i actually had to close the 20+ holes with tape when i converted into a greenhouse / jacuzzi room

I think they came because i keep 2-3 small areas of my yard totally wild to attract pollinators.
i cut down or pull up anything over 3-4 feet, but theres a ton of wildflowers, dandelion, weeds etc...
so i get all kinds of bugs and pollinators here.