Setting Up a Mason Bee House: Spring and Summer
I hung a Mason Beehive on the side of my house over the weekend, right next to my tomato bed and a pot of petunias. Filmed the whole thing. Thirty seconds, start to finish, with no special tools beyond a drill I already owned.
While mason bees are the headline tenants of these hives, the tubes inside don't check ID. Any solitary bee that nests in small tunnels rather than building comb can move in, and over a season, more than one species usually does.
That's good news for me, because despite my best intentions to get this up back in early spring for mason bees, here we are well into summer. Mason bee season has already passed. But for the next wave of tenants—leafcutters and other solitary bees—the timing couldn't be better.
Getting your yard ready for solitary bees of all kinds
Exactly when each species shows up shifts with your climate and the weather in any given year, so there's no single date that applies everywhere. What doesn't change is the basic logic: get the yard ready, find a wall to mount the house on, provide a mud source nearby, and let whichever solitary bee is currently house hunting find it. Here's a quick rundown of who that's likely to be, depending on the season.
Mason bees and the springtime window
Mason bees (Osmia species—the blue orchard bee is a common backyard species) spend almost their entire lives as dormant adults, sealed in cocoons inside capped tubes while they wait out fall and winter. They break that dormancy in spring once daytime temperatures hold steady around 50 to 55°F for several days, beginning as early as February in mild regions and extending into April farther north and east.
Males emerge first, several days to a week ahead of the females, and wait near the entrance. Once mated, females get straight to work: provisioning a mass of pollen and nectar at the back of a tube, laying an egg, sealing the cell with mud, and repeating the process until the tube is full and capped.
A female's entire active season runs about four to six weeks and is often wrapped up by late May or June. The eggs she leaves behind hatch into larvae, eat their provisions, spin cocoons, and develop into adult bees by late summer. They then remain dormant until the cycle starts again the following spring. Almost the entire life cycle happens out of sight inside the tube.
Leafcutters and other summer tenants
Once mason bees finish for the season, leafcutter bees (Megachile species) are the most common second wave. They need warmer conditions to get going—generally consistent daytime temperatures in the 70s—so they don't usually appear until early to midsummer, typically from late June through August and sometimes into September in milder climates. A hive installed midsummer isn't behind. For these bees, it's right on time.
That's also where the real upside shows up. Mason bees do most of their work on spring bloomers, especially fruit trees. Leafcutters and the rest of the summer crowd pollinate whatever is blooming once the garden is in full swing: squash, melons, cucumbers, and the flowers in between. More solitary bees working across more of the season means better pollination coverage, and better coverage tends to show up in the harvest, not just in the flower beds.
You can tell leafcutters from mason bees by the caps on the tubes. Mason bees seal their nests with mud. Leafcutters chew small circles out of leaves—rose bushes are a favorite target, so a few notched leaves in the garden are a good sign, not a problem—and use those pieces instead. Their nest caps have a green tinge and a slightly ragged, papery appearance.
Small carpenter bees (Ceratina species) can show up too, often later in summer, and may produce a second generation during the same season in mild climates. None of these bees are aggressive. They're solitary, they don't defend a hive the way honey bees do, and most people never notice them beyond the capped tubes.
Find a south- or southeast-facing wall
Before I picked up the drill, I found a spot on a south-facing wall, four to six feet off the ground. All of these bees are cold-blooded, so the warmth from a south- or southeast-facing wall helps get them flying on mornings that might otherwise keep them inside, especially during the cooler weeks of early spring.
Mounting the house four to six feet up keeps the entrance above most ground-level disturbances, including curious pets, lawnmowers, and kids with sticks, while keeping it low enough for me to watch what's happening.
Each hive comes with a French cleat and screws. I drilled pilot holes, set the screws, and the house was up. A Mason Beehive is light, the hardware is simple, and there's none of the leveling fuss associated with a full honey bee hive setup. If you can hang a picture frame, you can hang this.
They need mud as much as they need flowers
This is the step many setup guides skip, and it's one reason these houses can sit empty even in good locations. Mason bees don't just lay eggs in the tubes. They seal each cell with mud, then cap the entire tunnel with more mud once it's full. It's the reason they're called mason bees in the first place.
If your yard consists mostly of dry mulch, gravel, or hardscape with no exposed, clay-heavy soil nearby, mason bees can have a perfect house but nowhere to do the actual masonry. I keep it simple: a small dish of soil near the house, kept damp. Wet down some dirt within a short flight of the entrance and let gravity and sunshine handle the rest. Leafcutters don't need mud because they bring their own building material, but mason bees won't nest without it.
The checklist
- Choose a south- or southeast-facing wall, four to six feet above the ground.
- Mount the house securely using a drill and the included hardware.
- Provide a source of damp, clay-heavy soil within easy flying distance.
- Leave the house up through summer and into fall. If you miss mason bee season, don't worry: leafcutters and other solitary bees may just be getting started.
- Read Mason Bee Revolution to learn about the many different kinds of solitary bees.
Our Mason Beehive is built from western red cedar with replaceable paper tube inserts, so you can remove a season's cocoons each fall and start the next year clean. Set it up in early spring for mason bees or in midsummer, like I did, for leafcutters and other solitary bees just getting started. Either way, more pollinators working throughout the season usually means a fuller harvest, not just a few extra flowers.
