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How to Successfully Raise Mason and Leafcutter Bees

How to Successfully Raise Mason and Leafcutter Bees – This is the second of three useful guest blogs by our pollinator-supporting friends over at Crown Bees of Woodinville, Washington.


Mason and leafcutter bees are solitary hole-nesting bees that are effective pollinators because they carry pollen loose and dry on their hairy bellies. Both are easy to raise, fun to watch, and safe for families and pets. The steps for raising both bees are fairly similar and each bee is active during a different season. Mason bees emerge from their cocoons in the early spring and are superior pollinators of apple, pear, almond, cherry, blueberry, and strawberry plants. Leafcutter bees emerge from their cocoons in the early summer and are great pollinators of squash, melons, peas and other summer fruits and vegetables. Both bees are generalists and they will visit lots of different flowers in your garden!


Setting out leafcutter cocoons only takes a few moments!



The steps for raising mason and leafcutter bees are pretty easy:

  1. Install the bee house and place out cocoons.
  2. Bring in filled nesting materials and protect them from pests.
  3. Harvest cocoons in the late fall or early spring.
  4. Return healthy cocoons to your garden for more pollination.


All of Crown Bee’s products arrive with detailed instructions. You will chose dates for shipment of your bee cocoons. The bees need consistent daytime temperatures: 55*F for mason bees and 75*F for leafcutter bees. Remember to think about when your plants are blooming and pick your dates so the bees arrive a little bit before flowers start to open.



 Garden Tower Bee Cabin Leafcutter

The Bee Cabin with reeds. 



Here are more details about the steps and some great tips for success!


1.     Install the bee house and place out cocoons.


Chose a south-east facing wall that gets morning sun and some afternoon shade. Bees are cold-blooded and they need the sun’s warmth to get going. Install the house at eye-level so that you can easily watch activity. Installing the bee house is easy, like hanging a picture or putting up a birdhouse. Mason and leafcutter bees have a short flying range of 300 feet, so ensure that your Garden Tower is nearby the bee house.


Place out nesting materials: mason bees prefer the larger 8mm sized holes and leafcutter bees prefer 6mm sized holes. You will use the same bee house for both bees since they are active during different seasons. Just swap out the nesting materials for each bee species.


Once nesting materials are in the house, place the cocoons on top of everything and towards the back. We want the bees to crawl over their new homes as they emerge so that they know where to come back. Make sure you don’t place cocoons into direct sunlight!


Female mason bees require moist clayey mud for building their protective walls between nesting chambers. If your soil is too sandy or has too much humus you should supplement with the dry mud mix included in your BeeWorks kits. You are looking for a texture of soil or mud that sticks to itself when pinched with your fingers.


2.     Bring in filled nesting materials and protect them from pests.


Female mason bees are only actively flying for 4-6 weeks. Once a female is done filling her nesting hole with next year’s bee eggs, she caps the end of the hole with an extra thick layer of mud. You want to protect filled and capped nesting materials from ants, birds, and parasitic wasps. Protect the filled materials by placing them into a fine mesh bag called the BeeGuardian. Store in a warm garage or shed that has similar temperatures as the outdoors. The mason bee larvae need summer warmth as they feed and develop.



The BeeGuardian bag protects against ants and parasitic wasps.


Female leafcutter bees also only fly for 4-6 weeks but because leafcutter bees are able to sometimes develop quickly and emerge in the same summer they were laid, their season of activity is much longer. At the end of summer is when you can be sure they are no longer flying and that is when you will remove filled leafcutter materials and store in the fine mesh BeeGuardian bag through the fall and winter. Store in a cool garage or garden shed. Because of their delicate nature, you will not harvest leafcutter cocoons until early spring.


Harvesting cocoons from lake reeds is easy and ensures your cocoon’s health.




3.     Harvest cocoons in the late fall or early spring.


In the Pacific Northwest, mason bees spin their brown waterproof cocoons by the beginning of October. Harvesting cocoons helps maintain bee health by removing three big pests: pollen mites, chalkbrood (fungal infection), and parasitic wasps (typically a species called monodontomerus). Mason bee cocoons can be washed in a mild bleach solution to remove chalkbrood spores.


Leafcutter bee cocoons should not be harvested until early spring, around the time that mason bees are placed out. Leafcutter cocoons are not waterproof and leafcutter bees hibernate as larvae so their cocoons are more delicate. Harvesting leafcutters in the spring can help give any mason bees that had somehow nested interior of leafcutter cocoons a chance to emerge.


To learn how to harvest cocoons from all nesting materials and how to wash mason bee cocoons, see this page for photos, instructions, and videos.


4.     Return healthy cocoons to your garden for more pollination.


Mason bee cocoons should be stored in your fridge to ensure that they spend the winter in a consistent temperature. Crown Bee’s Humidibee container (included in BeeWorks kits) is designed to keep mason bee cocoons humid but not too wet.


In the spring, when daytime temps are consistently above 55*F and your spring flowers are blooming, set your harvested and cleaned mason bee cocoons out.


You will need to incubate leafcutter cocoons in your home. Plan for it to take about 6 weeks at indoor temperature of 70*F. For more tips on leafcutter incubation see this page.


Raising mason and leafcutter bees really only takes about an hour per year and you’ll probably end up spending more time standing next to their bee house watching them come and go. You can sign up for Crown Bee’s monthly newsletter called BeeMail for tips, advice, and reminders for what to do each month.


Ensure your garden’s pollination

Raising mason and leafcutter bees will help your garden grow more and grow better fruit and vegetables. Many flowers need to be visited many times in order to grow fruit at all. For example, a pear flower needs to be pollinated 30 times to make fruit! A flower that is properly pollinated will grow fruit that is rounder, fuller, and healthier. Adding a different bee species to your garden or farm can increase your yield by 24%! All of the effort that you put into your garden will be rewarded when you raise gentle solitary hole-nesting bees.



Want to get started?


See our native bee keeping supplies and pollinator kits at this link:


(Click here)





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