Keeping (Native) Mason Bees

What Are Mason Bees?

Mason bees are beautiful, gentle native bees that are also excellent pollinators. Before honeybees were brought over from Europe; native bees, like mason bees, did all the pollinating here in North America. Mason bees do not produce honey – they collect pollen, whereas honeybees collect nectar. Because a mason bee’s whole body is hairy, it collects more pollen and when they land on a flower they tend to ‘splash’ which helps them pollinate better than other species. Additionally, they’re actively looking for pollen, making them 3x better pollinators than honeybees. Another key difference from honeybees is the mason bee doesn’t live together in a hive, instead living solitary with no hive to protect. They’re a bee that’s active early in the season and pollinates throughout the spring.

Mason bees only have a range of about 100 meters; so they benefit you and your close neighbours. They’re extremely friendly and can be great for kids who want to stand close to the nest and watch the bees in action. They’re highly unlikely to sting and if they do it’s more like a pinch or mosquito bite.

Overall, mason bees are some of the original pollinators here before European honey bees were introduced, they’re gentle and they’re amazing pollinators. If that sounds like a bee you’d like to make a home for in your yard, then we have some tips for you!

Mason Bee Lifecycle

Understanding the mason bee lifecycle is essential if you’re hoping to care for them properly.

• Mason bees emerge from their cocoons in the spring, usually in March or April, and mate.
• Females construct nests in pre-existing holes, such as hollow plant stems, holes in wood, or artificial nesting tubes, by creating a series of cells separated by mud partitions.
• The female lays an egg in each cell and provides a mass of pollen and nectar as food for the developing larvae.
• The eggs hatch into larvae, which feed on the pollen and nectar provided by the female.
• The larvae spin cocoons around themselves and pupate.
• The pupae develop into adult bees, which stay in their cocoons until the following spring.
• Once the weather warms up in the spring, the adult bees emerge from their cocoons and start the process all over again.

How to Care for Mason Bees

Keeping mason bees doesn’t have to require a lot of time. We’ve rounded up a bit of a bee care calendar to show you some season-by-season care tips:

Spring Care:

• If you’re starting with purchased cocoons, wait until daytime temperatures are consistently above 55°F (13°C) and there are plenty of flowers blooming before releasing them.
• Watch as your bees emerge from their cocoons, males are usually the first bees to emerge and the larger females can take an extra couple weeks.
• In the spring, set out your mason bee house in a good east facing location with morning sun, afternoon shade and lots of flowers nearby.
• Provide a source of wet clay for the bees to use as mortar to seal their nests.
• If you’re using reusable tubes or blocks, make sure they are clean and dry before inserting them into the house.
• Monitor the activity around the house and make sure there is plenty of pollen and nectar available for the bees.

Summer Care:

• Continue to monitor the activity around the house and make sure there is plenty of food available.
• Ensure the house is placed somewhere that it receives shade during hot afternoons to prevent overheating.
• If mites are a problem, you may need to remove and replace some of the tubes or blocks in the house.

Fall Care:

• In late fall, harvest the cocoons from the tubes or blocks in the house. Carefully remove them and clean off any debris or mites (see below for specific instructions to remove mites).
• Store the cocoons in a cool, dry place over the winter, such as in a paper bag in the refrigerator to ensure they stay dormant. 
• Clean out the tubes or blocks in the house and replace any that are damaged or moldy.
• If you had mite problems, you may need to treat the tubes or blocks with a mild solution of bleach and water before reusing them.

Winter Care:

• Store the cleaned and dry tubes or blocks in a dry place until spring.
• Keep an eye out for signs of mold or other damage, and replace any damaged tubes or blocks before spring.
• Check on your mason bee cocoons periodically to ensure they are dry and free from any missed mites or mold. 

How to Remove Mites From Mason Bee Cocoons

If you happen to see mites (these sometimes look like sawdust) when harvesting your mason bee cocoons, there are a few ways to remove them. One way is by using diatomaceous earth. 

Here are the general steps:

• Obtain food-grade diatomaceous earth. This type of diatomaceous earth is safe to use and won’t harm the bees or the environment.
• Put the mason bee cocoons into a container.
• Sprinkle the diatomaceous earth over the cocoons until they are covered.
• Shake the container gently to make sure that the diatomaceous earth is evenly distributed.
• Leave the container with the diatomaceous earth and the cocoons for about a week.
• After a week, carefully remove the cocoons from the container and brush off the diatomaceous earth.
• Inspect the cocoons for mites. Any mites present should be dead or dying, and can be removed with a soft brush or gentle blast of air.
• Store the clean cocoons in a cool, dry place until they are ready to be released in the spring.

It’s important to remember that although methods for mite removal can be effective, the best solution is prevention! Make sure your bee nesting materials are clean and sanitized if you’re reusing them. 

What Flowers Attract Mason Bees?

Mason bees are generalist pollinators, which means they will visit a wide variety of flowers for nectar and pollen. They are especially attracted to flowers that are blue or purple in colour and those that have a tubular shape. It’s always a good idea to make sure you have a mix of flowers that bloom at different times throughout the year so that your bees have a steady supply of nectar and pollen, which will encourage them to stick around your yard. 

Flower Suggestions for Mason Bees: