FALL/MID-WINTER
Orchard Mason & O. californica
After October 1st your bees will have reached adulthood. Handling will not hurt them. Push the white liners containing bees out of the guard tubes from the back... remove the black plastic plug and push the liner out. Place these liners containing bees in the waterproof containers you plan to use to set them out in next spring.
Waxed milk cartons or one-liter plastic soda bottles with the tops cut off work perfectly to hold the bees in their white paper liners. Align all the tubes with the front (exit) pointing out of the container. Mark the exit end of the liner with a pen as you remove the bees from their cardboard tubes.
Store these containers filled with your hibernating bees in a cold out building or a refrigerator. 38 degrees is perfect! Don't worry about the occasional cold snap - bees can survive the occasional freezing temps.
The next step is to refill your old cardboard tubes. Place new white paper liners into the empty cardboard tubes. Secure them in place with the black plastic plug. They can then be put back in to your nester box. Leave them inside where they will stay dry until you put them out again in the spring.
SPRING
When day time temps reach a consecutive 55 degrees it is time to put your hibernating bees outside. This generally happens in March in the Pacific Northwest. Place the hibernating bees in their tubes outside in the best location (South side of a building under the shadow line of the eve) and watch the magic happen!
Enjoy!
Many thanks to Knox Cellars for all the great Mason Bee information!