Face nesting blocks as close to the southeast direction as possible to catch morning sun and affix it firmly so that it does not sway in the wind. It should be located at least three feet above the ground. These bees need mud to construct cell partitions, so adding a mud supply may be helpful. This can be a trench or tub located nearby where muddy soil is maintained during the nesting period. The mud should not be highly organic or sandy.
Clay soils work well.
Do not move the blocks during the weeks of active nesting. Once all nesting activity has stopped, the nesting block may be moved to a shelter such as a shed or unheated garage. Be gentle when moving occupied blocks at this time of year. This will give the bees added protection from predators and parasites, yet will allow them exposure to the cold temperatures that they need to break hibernation. If desired, bee emergence can be delayed for a short period by refrigerating the block in the spring until you are ready for the bees to emerge.