What Happens After Mason Bees Hatch?

You purchased or build everything mason bees will need; a house, the tubes and cocoons. And you’ve probably read about how to set up their nest to make sure that they hatch. But what’s next?

When Do Mason Bees hatch?

If you found a good location for your mason bee house (partial sun and sheltered from rain) and have healthy cocoons, your bees should start hatching early spring when outside temperatures start rising. The males will chew their way out of their cocoons first. The bigger females will follow shortly after. Immediately after hatching they will start looking for food. Are your plants not in bloom yet? We recommend placing a cotton ball sitting in sugar water (like in a small pop lid) and place it close to your mason bee house. This provides a food source until your garden is able to provide enough flowers for the bees to feed themselves.

The New Generation Of Mason Bees

To create a protected space for her to lay her eggs, the female mason bee starts off by building a mud layer in the tube. Think of this as a wall that keeps each egg separated. Next she places food (nectar and pollen) in the tube and lays her egg. She finishes off with another mud layer for protection. Each egg has their own little room and food supply. This process is repeated until the whole tube is full. If she still has more eggs to lay she’ll find a new tube and continue to lay eggs until she runs out. Each tube is marked by the mason bees scent. This warns other bees that it’s taken, and they’ll find a different location for their eggs.
Something really cool about mason bees is that they lay the female eggs in the back of the tube, and the males in the front as they will hatch first. How cool that the mason bees know the gender of their cocoons before they even hatch!


Male mason bees also start looking for nectar directly after hatching. Not to feed new eggs, but to feed themselves. While the mason bees are happily flying around looking for nectar rich flowers and pollen, they are pollinating your garden. It only takes two or three mason bees to pollinate an entire apple tree! 

The End Of Mason Bee Season

Around June you’ll notice that the mason bee activity is coming to an end. The life span of these gentle bees is around 6 weeks, which makes their pollinating season a short one. To prolong the time the mason bees are active in your garden, set out half of the bees when the weather is warming up and the other half two weeks after that. 
If you have had a healthy mason bee season, the tubes are now filled with the next generation of mason bees. They have received one final layer of mud for extra protection. Over the next couple weeks the eggs will start spinning their cocoons and will develop from pupae into full bees. It is now too cold outside for them to hatch so they will stay dormant until next spring when the weather warms up again.

Collecting Your Mason Bees

We recommend taking your mason bee house inside in July to prevent wasps and woodpeckers from eating your cocoons.  Simply take the house out and place it in your garage for the remainder of the summer.  In the fall you’ll need to do a little maintenance on the cocoons. The cocoons that have been secured in the nesting tubes are now fully developed and can be removed and cleaned in water.  Simply remove all the cocoons, and place in a small bowl.  Fill with water and stir the cocoons around in the water, continue doing this with fresh water until the water runs clean.  This will remove the pollen mites on the outside of cocoons that can kill your mites over the winter. Once you’ve finished place the cocoons on a paper towel to dry.  You’ll then put them in a container (not air tight, to prevent molding) and keep them in the fridge over the winter, this will keep them dormant through the colder months.

Maintaining Your Mason Bee House

Throughout the year mason bees require very little care, but we do recommend cleaning their house as stated above to prevent mite infestations.  It’s estimated that after 3 years a mason bee house will be so infested with mites that it’s unlikely any cocoons will survive.  Simply following the above steps will help increase their viability exponentially.  Learn more about how to set up your mason bee house and maintaining it here.