February 20, 2017 2 Comments

Between our recent videosand blog posts, by now you know a fair bit about the lifecycles and behaviors of mason and leafcutter bees. Now, let’s talk about keeping and caring for them!

Where to Put Your Mason Bee House

Once you have your mason bee house, the first step will be deciding where to hang it. The optimal location to hang your mason bee house is 6 to 7 feet off the ground, preferably under the eaves of your house or some other shelter. If this is not an option, choose a house design that provides adequate shelter from the elements on its own, like the
WBC Mason Bee House or the Lean-To Mason Bee House . These can be hung somewhere like a tree or fence post.

We also recommend that you hang your house so it gets south or southeastern sun exposure. Morning sun exposure will encourage your bees to start foraging earlier in the day without needing to extend excess energy. This is because bees are ectothermic, meaning their bodies do not regulate and retain heat; They do, however, need a body temperature above 90°F in order to fly. Thus, they warm their bodies in the sun and by vigorously vibrating their flight muscles.




Tubes and Nesting Trays

Next, you will need to equip your bee-house with tubes or nesting trays. While some people use solid wooden houses with drilled holes for nesting, this type of habitat does not allow cocoons to be harvested, and there tends to be significant buildup of debris and disease in the holes after being used for multiple seasons. We recommend selecting nesting tubes or blocks that can be opened—harvesting, cleaning, and storing your cocoons at the end of the season is the best way to ensure bee health and populations for the next year.

Some options for tubes to use include natural reeds,
cardboard tubes with or without a paper insert, or any rigid and breathable material like printer paper rolled around a pencil and fastened with tape. Providing tubes with a range of diameters is the best way to provide habitat for the widest range of native bee and beneficial wasp species. Once cocoons are harvested, however, tubes will need to be replaced.

Alternatively, you can choose to provide your bees with wooden nesting trays . Our trays are easily opened for cocoon harvest and can be cleaned and reused for years to come. Nesting blocks and tubes can be provided interchangeably, and can be mixed and matched inside the enclosure.

You will also need to make sure your bees have the right nesting materials available to seal up development chambers inside the tubes. Mason bees require mud with a heavy clay texture. If this is not naturally occurring in your area, you can purchase bags of clay-mud to mix and put out for your bees. They are sensitive to the moisture level of the mud, so be sure to water it frequently. Leafcutter bees require leafy or petal material to cut and bring back to the nest. They seem to prefer pea plants, roses, lilacs, and dahlias.

Forage and Nesting Material

Your next considerations will be ensuring that your bees will have plenty of forage and nesting materials within their 300 foot foraging radius. Mason and leafcutter bees are generalist foragers, meaning they gather nectar and pollen from many types of flowers. Make sure you provide a variety of plants with staggered blooming periods so that they have forage throughout the season.

Lastly, we recommend avoiding hybrid plants. These tend to produce less nectar and pollen, and will not provide a good quality diet for your bees. Visit your local nursery, and check out the
plant lists from Xerces Society to curate the best garden for your bees and other native pollinators.Also keep in mind that the best plants for native bees are native plants! Native bees have spent thousands of years co-evolving with native plants, so they are best at collecting nectar and pollen from those flowers.

Getting Mason Bees

Now that you have your house set up, it’s time to introduce the native pollinators to their new home! You can purchase cocoons for blue orchard mason bees and alfalfa leafcutter bees, often available through local breeders and nurseries. We get our cocoons from Crown Bees in Seattle Washington. These cocoons can be purchased at our Portland shop during Mason Bee Day , a special celebration we’re hosting on March, 11th!

Alternatively, you can attract local bees to your nesting site with nest scent pheromones . These are most often available in the form of cotton sheets infused with cocoon dust. We recommend purchasing cocoons and using an attractant at the same time, as it may draw even more local bees to join the aggregation. Mason bee cocoons can be released when temperatures reach above 50°F consistently in your area. Place the cocoons on a ledge near the habitat, or in a designated space within the bee house, like an attic. Adult bees will emerge conveniently near an ideal nesting site, and are very likely to move in.

We recommend releasing your cocoons in two waves. The first half should be released right when optimal temperatures are reached, and the second half should follow two weeks later. This will extend your spring pollination season, increasing your garden yields.

Males are smaller than females, and emerge first. They forage for nectar and return to the nesting site to await females. Before releasing portions of your population, make sure you have more small than large cocoons. This will ensure there are enough males for your females to mate with.

Getting Leafcutter Bees

You can begin Leafcutter bee aggregations in the same manner, but later in the season. Release these cocoons when temperatures reach a consistent 70°F. Once everything is set up and your bees are active, they will take care of themselves entirely for the rest of the season.






End of Mason Bee Season + Harvesting

Mason bee season is over when tunnels are capped with mud. This usually happens by early summer. You can choose to move capped and sealed tubes into a protective and breathable bag to prevent predation and parasitism. Store this bag in a warm location where they will not be disturbed. Otherwise, leave sealed tubes in place and undisturbed until fall cocoon harvest. While your bees may do well on their own and wake up when the next season begins, harvesting and cleaning cocoons is the best way to prevent diseases and parasites from spreading.

To harvest, simply open the tubes or nesting blocks and scrape out nesting materials. Then, sort the cocoons from the debris. Be sure to do this in a cool place—you do not want your bees to wake up early after being moved into a warm house! Any c-shaped cocoons should be separated immediately: these are likely affected by chalkbrood, a fungal spore disease that spreads readily.

Wash the cocoons in a cold water bath. If any chalkbrood was found, add a quarter cup of bleach per gallon of water to kill the fungal spores. Any cocoons that sink in the bath should also be separated and discarded. Keep an eye out for cocoons with small holes. These may have been parasitized by wasps, and should remain separate from the healthy bees.

Cocoons can then be stored in the refrigerator between 30 and 40°F, and should be maintained in an enclosure with around 60 to 70% humidity. Crown Bees’ Humidbee is a container specifically designed for this purpose. Cocoons can be stored like this through the winter, until temperatures break 50 degrees. At that point, they can be placed outside near their nest to begin another season.

End of Leafcutter Bee Season + Harvesting

Leafcutter bees will remain active until late fall. Once you stop seeing active adults, remove their nesting blocks or tubes and place them in a breathable bag. Store them in a cool location like a shed, basement, or garage through the winter.
Overall, increasing native bee populations in one of the best ways to support local ecosystems and increase your garden and fruit tree yields. Keeping mason and leafcutter bees and providing habitat and forage for other native bees is an easily attainable and rewarding experience you will not want to miss out on!Leafcutter bee cocoons can be harvested in early spring, when adult mason bees are waking up. Separate cocoons from debris, and store in breathable bag in a warm place. Do not wash leafcutter bee cocoons because they are not water-resistant. Four weeks before your summer garden begins to bloom, place your cocoons in a location with consistent, warm temperatures of around 80°F. This allows them to pupate, and your adult bees should be ready to emerge in about 28 days, when they can be placed outside near the nesting site.

2 Responses

Tim Dunahoo
Tim Dunahoo

April 08, 2017

I received bees in tubes and need to know, do I release them by placing the tubes in the house or do I open the
tubes and get the cocoons out in order for them to be released ? Thanks for your help! Tim


February 23, 2017

Really good write up. One question
How do I keep yellow jackets from moving on also? Thanks :)

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