What is a Mason Bee?
Meet the California Blue Orchard Bee, commonly known as the Mason Bee!

What is a Mason Bee?
The name “Mason Bee” comes from the female’s mortar-like application of mud to seal off her egg chambers. Mason Bees are gentle, solitary, and non-aggressive bees, making them an excellent garden companion! They are tremendous early season pollinators, especially during the fruit tree bloom time. They can improve the fruit set of nearly every plant within 100 yards of their home!
The female mason bee lives a solitary life, foraging nectar and pollen for her 30-35 eggs. Her adult lifespan is about 4-6 weeks. The male mason bee emerges from his cocoon for one exciting moment of spring mating, then perishes.
Mason Bees VS Honey Bees
- Mason bees have more hair, and collect dry pollen all over the underside of their abdomen to scrape off later in the hive, instead of wetting and sticking the pollen to their legs like the honeybee.
- They are solitary bees with no queen.
- Female mason bees have stingers but rarely use them.
- They even work in cool, rainy weather while honey bees remain in the hive.
- They have black bodies, enabling them to warm up in the sun faster.
- They are less susceptible to disease than colony forming bees.
- They have a shorter lifespan and die in late spring.
- They produce no honey or beeswax.
Where to Place Your Houses:
Ideally, your mason bee houses should be placed in a south or east-facing location with access to plenty of morning sunlight. You don’t want your bees to bake in the afternoon heat. Place the houses about 4 to 8 feet off of the ground, and tuck them under an eave for rain protection.
Be sure to place houses near the food source (the plants/trees you want your bees to pollinate) as the flying range of a mason bee is short; anywhere from 100-300 feet. If you have a lot of fruit trees, consider placing several nesting boxes throughout your yard.
The female will need mud to secure her young in the nesting box, so providing a mud source nearby will encourage her to stay at your location to lay her eggs.
DIY House & Cocoon Cleaning:
Materials Needed:
-Bucket/Large Container with 1 Gallon COLD Water mixed with 2 teaspoons of Bleach
-Container with clean COLD water
-Sieve
-Paper Towels
-Dry Divided Container for Storage
If you wish to do it yourself and harvest your own cocoons, wait until the fall season (October/November) arrives then carefully separate the tunnel blocks and scrape filled tunnels with a dowel/closed pen tip/etc to remove the cocoons and all debris. Put all the debris and cocoons in the bucket with 1 gal of COLD water and 2 tsp of bleach. Gently stir then let soak for 5-10min. Stir again then using a slotted spoon or litter scoop, scoop out the floating cocoons and place in the clean cold water. Use a clean spoon to stir cocoons. Put the cocoons on a sieve/splatter screen and pat dry with a paper towel. Set the sieve on top of a clean container (to allow top and bottom airflow) to dry for 1-2 nights in a cool place, not in your house! Store the cleaned cocoons in a divided container, with one section dry, the other with a moist paper towel. (Make sure the container has some small air holes for ventilation.) Store in fridge and be sure to check periodically that paper towel remains moist. They are now in hibernation until you release them in the spring!
Clean the tunnel blocks using a flame lighter. Slowly run the flame over each tunnel chamber. This will remove any mites or fungus!
DO NOT submerge your house or tunnel blocks in water or bleach!
*If you do not wish to harvest the cocoons, you can wait until bees have hatched in early spring, then clean out the house and replace tubes accordingly before returning it to the location. This will encourage continued and safe use by the females.
Why Keeping Nesting Tubes Cleaned Is So Important:
The hairy-footed mite (Chaetodactylus krombeini) also known as a pollen mite, is a common parasite found on mason bee cocoons, and can be detrimental to both young and adult mason bees. While out gathering pollen, bees unknowingly pick up one of the hitchhiking female mites and bring them back to the nest, where the mite will lay eggs in the brood cells near mason bee larvae. The mites will feed on the bee larvae pollen stores, bee eggs, and larvae. When mites infest a nest and adult bees emerge from the infected nest the following spring, the mites can climb onto bees and hitch a ride to a new location. In the wild, mason bees rarely reuse the same nesting cavity. Having a thorough yearly “house cleaning” is quite important as a steward of these hard-working, wonderful pollinators. That’s all it takes to foster a healthy mite-free population for your overwintering mason bees, and promotes success for the next generation.

