Mason bees are pretty incredible: They’re docile, they are easy to raise, and they are amazing pollinators of spring flowering fruit and nut trees. These bees don’t use hives the way honey bees do, instead preferring to place their eggs in narrow holes, plugged up with mud (hence the name “mason”).
Their gentle nature and solitary habitat preferences make mason bees a great species to “keep” in your yard. That is, if you do it right. If you don’t do it right, you might be harming them more than you’re helping them.
Former evolutionary biology professor Colin Purrington took to X (then Twitter) a few years back to tell us all the ways our good intentions have gone awry, and it’s worth a reminder if you want to set up a mason bee house in your yard or garden this spring.
If you’re going to make your own mason bee house, Purrington offers his own tutorial here, along with a slew of additional reading you can take advantage of. If you’re leaning toward a store-bought variety, don’t simply grab the first cute structure labeled “mason bees” that you see. It’s important to educate yourself about the species first to understand how to most effectively help them—and not accidentally harm them instead.
How to properly clean a mason bee house
The biggest problem Purrington points out with some store-bought mason bee houses is that the blocks and reeds are glued to the back of the house. That means you can’t add new nesting material each spring, greatly increasing the risk of parasites and fungus.
You’ll find some great info here on the year-round care of mason bees, including storing the nesting tubes and blocks and harvesting the cocoons.
The best place to put a mason bee house
Mason bee houses should be placed against a flat surface in an area protected from high winds, approximately six feet off the ground and south-facing, if possible. Do not hang mason houses by a string from a tree limb; allowing the eggs to be knocked around in every passing breeze isn’t helpful. They’ll also need to be close enough to pollen-producing plants (they won’t travel farther than 300 feet), as well as a good supply of claylike mud to cover up their nesting holes.
The roof of a good mason bee house will have a bit of an overhang to protect the holes from rain and lower the risk of the larvae and pupae rotting inside the nest.
If you’re now questioning the quality of your mason bee house, you can always ask Purrington directly for his opinion (hey, he offered).
