Since I'm seeing flowers all over out there, including tomatoes and eggplants starting up, I took the mason bee cocoons out if the fridge, put them in the front of the house I made, and installed the house. I also sprayed some mason bee attractant on the house - hopefully, this will keep them here, and maybe attract more from around here.
Mason bee house hung up, with the cocoons slowly opening up. by pepperhead212, on Flickr

I collected some heavy clay soil, and put it in a container, with some drainage holes, and with something to prop it open, so the bees could get to it, then sprayed it with some more of that attractant.
Container of clay, for the mason bees. by pepperhead212, on Flickr

Clay container, propped opened so that the bees can access it. by pepperhead212, on Flickr

How long will the cocoons take to hatch?

[mention]PlainJane[/mention] Some have already started hatching - I hope they don't just fly off. The attractant should help, but I'll find out.

Fascinating, I’ve been seeing some metallic blue honey bee sized bees out in the garden and looked them up. Turns out they are Mason Bees, also called Orchard Bees, and are one of the native bees. Lots of different species of them. Read they are excellent pollinators. Good luck with the structure.

[mention]karstopography[/mention] Here's an interesting episode about mason bees that I saw on Grow A Greener World:
https://www.growingagreenerworld.com/ma ... evolution/

I've had them in my garden for a few years now with this season (Sept '19-current) more than ever. They are excellent pollinators for tomatoes and work all day long except when it is super windy (30MPH) or pouring out. I had such an early crop '19 fall because of them. It's like hot night time low temperatures mean nothing anymore. I love having them around and almost want to keep a tomato plant going throughout the summer to let them know they are appreciated.

Has anyone else seen the baby Mason Bees yet? They are so cute - just a tiny version of mom.