Made here in our wood shop using radiata pine, all joints are glued and stapled. Holds approximately 35 reeds (optional), or can also be used with cardboard tubes and liners. It has a key hole notch on the back for easy hanging with a nail or screw.
In our experience, mason bees prefer reeds over cardboard tubes or wood nesting blocks. The slight variation in size between individual reeds allows the female to pick a size of her choice, and it also encourages native pollinators to nest. This is beneficial if you are not buying cocoons and want to put out a house to try and attract some pollinators to move in.
Our natural Phragmite reeds are hand harvested, and cut to 6" length which is an optimal nesting length for mason bees. The reed hole sizes are about 8mm and approximately 6" long. At the back of the reed is a natural node that seals the reed and so helps prevent parasitic wasp access.
House dimensions: approximately 4.25" x 4.25" x 8.5"