Mason Bees

Although many of us tend to instinctively swat them away, bees can be an invaluable assistant to any backyard gardener. By housing mason bees in your garden, you can bridge the gap between person and pollinator, enjoying their ability to produce bountiful fruit harvests and beautiful flower beds.

Mason bees

The orchard mason bee, also known as the blue orchard mason bee due to its metallic blue tinge, is native to North America and tends to nest in existing holes or cavities.

“Mason bees are the unsung pollination heroes,” says Ian Lai, founder of the Richmond Schoolyard Society and principal of Urban Agriculture Consulting. “They are not distinct in terms of having stripes or fuzzy hair, and they almost look like a fly. They don’t produce honey—in fact, they produce no product at all. But they have an incredible ability to cross-pollinate.”

With honey bee populations in Canada having declined by over 30 percent, mason bees’ perseverance in pollination outshines their lack of yellow stripes. These insects can list hardworking at the top of their resumés—they are thought to be 10 times more efficient than their honey-producing buddies, with female mason bees visiting up to 17 flowers per minute and even working at lower temperature ranges.

So if you find yourself wondering, “To bee, or not to bee,” there need not be a question—mason bees can be a proficient addition to a variety of gardens and homes.

A friendly addition

There is good news for parents and pet owners: introducing mason bees into your garden doesn’t mean having to tiptoe around in fear of being stung. Male mason bees are not capable of stinging, and females will not display aggressive behaviour even when cornered at their nests.

“Mason bees are incredibly docile,” explains Lai. “I’ve been working with mason bees and children for years, and have never had a single case of someone being stung.”

Life cycle and care

Winter

Bringing them in

Building suitable homes for the bees outside (see sidebar for tips on proper bee housing) can often attract mason bees on their own around mid-March.

However, if you would like to get started on your un-bee-lievable journey right away, you can purchase dormant mason bee cocoons from your local garden store or order them online from a reputable source. The time to get them is around January or February, so they can remain safe and cocooned until the spring—but don’t wait too long, as their growing popularity means they frequently sell out.

Although seemingly unorthodox, it’s best to store your new bee buddies in the fridge. The cooler temperatures will ensure they do not emerge before flowers begin to bloom.

Spring

Weather woes

The key to a successful mason bee season is timing—put your cocoons out during a streak of sunny weather, as the bees are reluctant to fly when it is raining.

“Make sure that you bring them out of the fridge when it’s warm enough, and when there is enough pollen and nectar around to sustain them,” says Lai. “They won’t emerge right away, so a streak of four to five days of good weather is best.”

Lai tends to let his bees emerge a little later, just to be on the safe side. Try to wait for a dry, mild day with little wind, preferably with temperatures above 59 F (15 C).

Emergence

The warmth of spring brings some tough love. Male bees, recognizable by a small tuft of white hair on their foreheads, will emerge from their cocoons first and wait a few days or weeks for the females, only to mate and then die. Females will then get to work laying their 30-or-so eggs; luckily for garden owners, the pollen and nectar collected from plants make for wonderful nourishment and padding.

Pollination

Mason bees have a particular affinity for plants that produce apples, blueberries, pears, and stone fruits such as cherries and peaches. They thrive in urban settings with short flight paths; having a variety of native or heirloom plants available will also ensure maximum pollination and biodiversity.

“It’s like a good investment portfolio—you don’t buy only one kind of stock,” says Lai. “Bees should have a diet of varied plants.”

Try growing chives, cranesbill, lavender, sunflower, or bugloss to attract bees in spring. Visit feedthebees.org for a comprehensive list of bee-friendly plants.

Nesting

Females will use existing holes in wood as nests for their eggs. Each egg is placed on a gathered pollen patty in the hole, and the female will seal off the entrance with mud.

Summer and fall

The lifespan of female mason bees is about four to six weeks, as they die after the tiring work of laying their eggs. Eggs develop into pupae over the coming months, eventually spinning themselves into cocoons.

As leaves turn orange with the onset of autumn, it’s time to take out the nesting tubes and give the cocoons a gentle cleaning to ensure that pollen mites do not damage the transitioning bee pupae still inside. A mild solution of eco-friendly oxygen bleach and water is harmless to the cocoons and boosts chances of a successful emergence in the spring. Store the cleaned cocoons within a padded paper box, inside a jar, in the fridge.

A unique connection

The benefits of mason bees extend beyond pollination—caring for the creatures can foster a unique connection with both insect and garden. Lai says that working with children and mason bees helps them to better understand their part in the ecological processes all around us.

Emily Vera, a preschool teacher from Richmond, BC, who purchased mason bee cocoons for her own home before embarking on a preschool mason bee project, sees a similar connection. “The act of washing and storing the cocoons teaches children about showing responsibility and respect, not only to the bees, but to all living things,” she says. “This process allows us to connect with them and care about them. I have lain awake on rainy nights because I was so worried about the bees!”

Housing

Mason bee homes should be placed facing southeast, as warmth in the morning is important to get them going for the day. Be sure to keep the homes 4 to 10 feet (1 to 3 m) off the ground, in a spot that is dry and well protected from wind and rain. If you’re interested in watching them emerge, feel free to place them at eye level if the spot is suitable.

Commercial bee homes are available in a variety of shapes and sizes, depending on how many bees you would like to house. Many of them can be painted—just be sure to use nontoxic paint.

You can even make a mason bee home yourself, using a wooden block with drilled holes, or using cardboard and paper for the nesting tubes. “Mason bees are cavity dwellers, so you have to watch the length of the tubes,” advises Lai. “They don’t like super long ones, so keep tubes around the width of a pencil, but a bit shorter in length.”

(image source: Wikipedia)