Due to disease and other factors, bee populations are declining, and fewer pollinating insects means trouble for crops and wild plants alike. You can help counteract this trend by building a simple home for orchard mason bees, a wildly productive pollinator found in most areas of the United States. The house offers holes sized perfectly for mason bee nurseries.
Mason bees are gentle, they don't swarm, and they rarely sting, making them a considerate guest in your garden. They lay eggs in the spring, so be sure to get your house out early.
Measure, mark, and saw off section 1 from the board, as shown in the diagram. Use it as a template to mark and saw the five matching pieces.
Stack the six pieces and temporarily wrap them with tape. Place the taped stack vertically on the remaining board and mark the base. Saw along the line. The remaining board is the roof.
Use the hammer and nails to attach the base and roof to each of the six pieces. Make sure the back of the roof is flush with the house's back. Remove the tape.
Mark holes every 1-1/2 inches on the front of the vertical pieces, then drill a hole 3 to 8 inches deep at each mark, avoiding nails. (The bees lay female eggs in the backs of the holes, male eggs closer to the front.) It's easier to drill the shallower holes on the outer boards. Smooth the openings with the sandpaper. Knock the sawdust from the holes.
Using the picture-hanging kit, mount the house facing south or southeast on a wall, fence, pole, or other support. Look for telltale mud walls inside the holes over time. Next spring, full-grown bees should emerge.