03/16/2026
CHEAP EASY MASON BEE HOUSES
As soon as late winter weather will allow, scout out accessible patches of invasive phragmite (common reeds), put on some muck boots and bring a good pair of shears. If you have to drive, bring the boots with you and change in and out of them at the car. I have "TEMU special" power shears that take all of the strain out of repetitive cutting. Wade into the reeds, keeping out of the water if possible, looking for the largest diameter, clean looking stalks (relatively free of black schmutz). Grab, squeeze, and bend them, and if they crush or snap, break them off, toss them, and move on. When you find a strong one, cut it low, below a node and set it aside.
When you have an armload (you'll need more than you think), take them to open dry ground cut the tops off where the stalks get too thin so you don't bring home seeds and spread them.
When you get home, the stalks will have grass sheaths attached at the nodes. Grab the stalk firmly with one hand and grab a grass sheath with the other and twist it like a motorcycle throttle with your fingers. It should snap free, leaving a smooth, clean tube beneath. Repeat for each segment until all of the stalks are clean.
Now you need a thin, fine-toothed saw, preferably a band saw or scroll saw (I have both and prefer the band saw), but a hacksaw in a miter box might do the job (I'll have to test that out). I think a table/radial arm/chop saw might be too rough. Cut the stalks in half, just below a node, then cut the more manageable lengths just below each node until all of the stalks are reduced to 7-9" segments, closed at the node end, which will keep out Houdini flies and other predators/parasites after the front of the tubes are sealed.
Here's where it could get tricky and why you need more reeds than you think. The node cuts are usually clean, as this is the thickest part of the stalks, braced by the interior floor of the node, but now you need to cut the segments to length and the thin, unsupported walls of the open ends are prone to cracking. The up and down vibration of my scroll saw can grab individual fibers and pull them away, leading to cracking, while the band saw's single direction blade pulls the tubes down against the solid cutting deck, which supports the thin walls so they can't flex and crack, but it still happens.
Mason bees prefer tubes about six inches deep. Female workers will always lay male drones at the front of each tube, so if you make your tubes shorter, you will get a higher ratio of drones to workers. You can measure one six inch tube, cut it to length and use it as a template to measure all of the following tubes, placing it against the uncut tubes with the node ends lined up flush. You can also create a quick and dirty jig by clamping a scrap wood fence to the cutting surface six inches from the blade, using a 1x4x12+ scrap as a miter fence/pusher block, and then put the uncut tubes in front of the pusher block and slide it along the fence into the blade, only allowing the blade to nick into pusher/fence. If you are using a miter box, you can clamp a stop six inches from the cutting slot so you just drop in a tube, pull it against the stop and the wall of the box, and cut.
Now you should have a mountain of clean, six-inch tubes sealed at one end. Be prepared to throw away more tubes because the inner diameter of some of the tubes will be too small. The ideal diameter is 5/16" (8mm), but can range from 1/4" (6mm) to 3/8" (10mm). I limit mine to 5/16" or larger, not worrying about being too large, as there are other compatible, beneficial bees that might want more room, like leaf cutter and carpenter bees. I grab a 5/16 (8mm) drill bit and insert it into the end of each tube. If the bit fits with a bit of twisting and doesn't crack, I'll keep it as the bees will clean out the frass to suit their needs: too small and I toss it.
Now you are ready to build the houses. Get light colored duct (duck) tape (black may be too hot in the sun) and pull off about a three foot strip, laying it on a clean work surface, sticky side up. It will try to stick to your fingers but it will come free and lay flat with a little effort. Begin by laying a tube in the center of the tape strip, lining up the bottom of the tube with the bottom edge of the tape, keeping it as perpendicular as possible (unfortunately, you can't use a miter gauge for obvious reasons). Add tubes to each side, keeping the bottom edges aligned and work towards the ends, like you are creating a giant pan flute, pulling off and resetting tubes if necessary, and leaving a few inches of tape at one end.
When finished, start at the completed end and tightly roll the assembly towards the bare tape and use that exposed tape to bind it into a cylinder. Wrap both ends in a full layer of tape and then overlay them with a strip(s) of tape in the middle, creating a waterproof cylinder.
To create a hood to keep rain off the face of the house, cut a strip of tape more than half of the circumference of the house and lay it sticky side up. Cut another strip about an inch longer, giving you tabs to hold onto as you lay it sticky side down on the first strip, forming a rigid, non-stick hood. Trim off the sticky tabs and any exposed glue along the length, so you don't trap any bees. Cut a strip of tape to the circumference of the house and lay it sticky side up. Center the hood piece lengthwise and overlap it onto the sticky tape by about 1/2 inch, leaving the balance free. Center the house on the sticky tape, and align the front of the house with the top of the sticky tape, leaving the non-sticky hood projecting above the house. Wrap the tape around the circumference, securing the hood in place.
Find a long nail that fits tightly between tubes at the back of the house, drive it shallow into a tree or other mounting surface, pointing away from the prevailing wind. Slide the house onto the nail near the top of the house, like you would a clock, cutting/nipping off the nail head if necessary.
Place a bowl of mud in the shade near each house for them to seal the tubes and check it regularly. Searching for mud takes away from pollinating and laying eggs.
Watch for Houdini Flies during active laying. They are slow, stupid, red-eyed flies that you can easily swat. The sneak into the tubes to lay their eggs and their larvae feed on the stores left for the mason bee larvae, leaving them to starve.
Build it and they will come. If you have an orchard, mason bees, leaf cutter bees, carpenter bees, and more are out there. Build a house and provide an easy source of mud and they will happily stay close to their source of food. You can buy pupae, but I've found that they are expensive and unnecessary.
As for managing larvae, I have a hands off approach. I leave them be, as nature intended, and simply provide them new clean houses every spring. You might want to cut the houses open and split open the tubes to clean and save the pupae in the fridge, protecting them from the Houdini fly and other predation.
For a cleaner look and a bit more money, wood grained vinyl contact paper would make for a more attractive house that might pass for a cut log at a distance. Cut a three foot by eight inch sheet of contact paper, peel off the backing and lay it sticky side up. I'd build up the house the same way as above, leaving a few inches at one end and an exposed two inch strip at the top, but before rolling it up, I'd cut a 1.5 foot by two inch strip of contact paper, peel off the backing, center it in the middle of the three foot strip and lay it sticky side down on top of the two inches of exposed contact paper at the top of the tubes. Then I'd trim away the nine inches of exposed sticky contact paper to each side of the hood, roll up the house and secure it with the tape end of the roll, leaving a single clean surface with an integrated hood.
