I'm rolling brown paper bags into Mason Bee Tubes. I haven't chosen a container, yet. But, I'm thinking a plastic ice cream tub with an extra brim to keep rain off. This is my first year, and I don't know whether there are many bees near me or not. I've been developing my native garden for 2+ years, so hopefully I'll have some residents. Martha

My question would be why you would want to keep them in your refrigerator that long. They are programed to come out at a certain time in the spring.

And honestly, they might just not live in your immediate vicinity. Mason bees travel short distances only, and they are very picky about local sources of mud and local composition of soil -- if they're going to nest, they want the right materials nearby to minimize their work and maximize their time reproducing. In western washington state, mason bees are widespread. But sites just half a mile away from each other can be vastly different in terms of performance. If you buy bees, they hatch, and they all leave (or "disperse") then well, it's just your site, and no matter how great you make the house they just wont show up to the party. :-/ Best of all, they like clay-y mud, despise sand, and like a natural source of wet mud like a nearby stream bank or reliably wet area. No amount of putting perfect material nearby makes them change their mind :-)

I was actually in the same predicament that you are in. It wasn't until I planted a bunch of native flowers and herbs that I really started getting tons of bees coming in. I researched what flowers were native in my area and then researched what seed company's had the flowers and herbs I needed. Lavender was the biggest hit in my garden. It took a few times of ordering until I finally found a great company that had all the seeds I needed and had the best germination rate. I've included the link to the website if you're interested. Eden Brothers