In my Backyard

Blue Orchard Mason Bees

It’s almost time to release my mason bees. They’ve been hibernating all winter in my fridge in their special humidibee container where they get a consistent winter temperature and a perfect level of humidity; where they are protected from predation and damage. I’m estimating that by the end of March, it will be consistently warm enough for them to come out of hibernation. It’s a careful balance, I want to let them out when it’s warm enough for them (when day time temperatures are consistently around 55°F) and there’s enough food for them.

I first started keeping Mason bees as a community gardener at the Colonel Summers Community Garden several years ago. My neighbor in the plot next to me kept bees and helped me get started and I’ve been doing this ever since. These photos are from a previous spring. My bee house is all set up – facing east to catch morning sunlight and help the bees warm up and get moving, its sturdy and sheltered to protect them from rain, wind and hot afternoon sun.

I have a few different types of nesting materials – all the correct size and material type for mason bees. I’ve also added a few twigs to give them a place to land and rest as well as to help them identify their own nest holes. All the nesting materials I’m using are specifically designed to allow me to collect and clean the mason bee cocoons in fall. Cleaning the mason bee cocoons and nesting materials is absolutely critical to the health and future of not just my bees, but all Mason bees. You can learn more about this and other ways to protect and keep mason bees healthy and safe here.

Everything is ready, now I just need the bees.

My bee house is all set up and ready for mason bees to move in.

Each female bee that emerges from her cocoon will find a male to mate with and then choose one of these nesting tubes to begin her work. She’ll spend the spring collecting pollen, rolling it into pea-sized balls, laying a single egg on the pollen-ball, and then building a protective mud wall to create a protective compartment for her egg. She’ll keep doing this until the whole tube is full and then she’ll move on to another tube and start the process again. Hopefully, by the end of spring, all the tubes will be full and I’ll have a whole batch of new bees growing and developing for next year.

Mason bee cocoons are placed in their hatching container.

I’ll place the cocoons in the hatching container I’ve made – nothing fancy, just a clean open space with a single hole facing out towards the light so they can easily find the exit. Below the next box, I have a small, shallow tray full of very fine silt mud placed conveniently close by so they bees can build their characteristic mud walls between each egg and pollen-packet.

I place the hatching container with it single hole facing outwards so the bees can easily find the exit.

I’ll release the bees in stages by placing successive groups of them in the hatching container. By doing this, I can extend the overall length of time spring-blooming plants get pollinated by my bees and I can spread out the available resources (food, polle, muds, and nesting tubes) for my bees. Before placing a new group in the hatching container, I remove the empty cocoons and any dead cocoons whose bees never emerged.

Here, you can see that the bees have already filled almost all the holes on the lower blocks and about a third of the tubes in the round canister and they are still going strong. I’ve added more nesting tubes so they will stay and keep working on the community garden. Even though I call them “my bees”, they are wild and if they don’t get what they need from me, they will fly off to find it themselves. It’s a partnership.

The bees filled almost all the holes on the lower blocks and about 1/3 of the tubes in the round canister so I’ve added more nesting material above.

It’s worth noting that mason bees and a number of other solitary bees (like leaf cutter bees) are actually much better at pollinating plants than honey bees. This is because honey bees collect pollen in tidy baskets on their legs while mason bees collect pollen by doing a literal belly-flop onto flowers. The pollen sticks to special hairs on their body and especially their lower abdomen. As they fly from one flower to the next, pollen is flying everywhere and cross-pollination abounds! Once they get back to their nesting tube, they have a special way of scraping the pollen off of their body using their hind legs and then they form the pollen in to a tidy ball.

Not only are Blue Orchard Mason bees absolutely adorable, they are rock-star pollinators who fly from flower to flower coated from head to toe in pollen.

Here’s an amazing video that shows what actually happens inside a mason bee tube. You get to watch a mason bee build her pollen and egg compartments!

You can learn all about Mason bees at – they have a stellar education section on their website that I highly recommend.