TOP POLLINATORS
Roll out welcome mat for mason bees
When I have questions about mason bees, my go-to-guy is Dave Hunter, owner of Crown Bees in Washington state. He’s not only incredibly knowledgeable about this species and many others, but he also has a passion for them.
Going from a key role in the real estate industry 11 years ago, Dave turned a hobby with mason bees into a very successful company and has become one of the leading resources for anyone needing help in raising these wonderful pollinators.
Hunter is devoted to continuous learning and generously shares his findings with anyone. He thinks big picture, and closely observes nature to better understand the roles plants, animals and insects play and how they are interconnected.
“I’m always working with science to learn what scientist are learning and applying that to my relationship with bees.
“Recently in Wisconsin, it was discovered that some bee eggs layered in pollen did not survive because there were no microbes in that pollen. Tracing back, it was discovered that some of the fungicides used to control diseases were also killing microbes in pollen, the lesson being keep fungicides away from plants that produce nectar and pollen for bees.”
With the growing concern for bee populations, in both the U.S. and Canada, and the National Pollinator Garden Network’s goal of planting one million certified pollinator gardens, is there much need for mason bees in our gardens? Should we not be focusing more on other bee species?
Hunter explains that, of the 4,000 native American bee species, none make honey. It was European colonists back in the 1600s who brought honeybees to North America for a source of sweetness in their diet. Honeybees carry pollen on their sticky hind legs, and it is taken back into the hive. They are pollen gatherers, not primarily pollinators.
Of the 450 or so native bee species in B.C., roughly 20 per cent, including mason bees, are hole-nesting bees, and their pollen is carried differently. When mason bees go foraging for pollen, they spill much of it everywhere as they travel from flower to flower. Because of this, native bees are pollen spreaders and the best cross-pollinators.
That’s why mason bees are so important: they pollinate a wide range of fruits and vegetables.
So what can we do in our home gardens, especially small-space gardens, to create a habitat for mason bees?
Hunter says we should have a good assortment of plants, a lawn, good soil and humus, and it’s critical to have a source of clay. If mason bees cannot find clay, they will simply fly to another location. If a garden does not already have some clay available, then a supply of clay should be brought in and buried just under the soil. It’s also important to poke a shovel handle-sized hole about 15 cm in the ground to provide access to the clay.
The most popular mason bees for colonizing are the clay-using blue orchard variety. There are mason bees in B.C. that use chewed-up leaf bits, downy parts from flowers and mixtures of them. In the wild, mason bees lay their eggs in small, natural cavities like woodpecker and insect holes, or in hollow plant stems.
We can also help provide vital egg-laying habitat by setting out specially designed mason bee houses. Even though putting up bee houses and having these bees pollinate domestic plants is an unnatural process, by observing what mason bees need to thrive, and by being creative, we can make a difference.
“It’s clearly not nature’s plan to collect all the mason bees in one spot, because it’s an invitation for their predators to come calling to one easy location,” Hunter says.
He recommends not having too many holes together in one place, and to provide small 4-millimetre and medium 6-mm holes for the tiny mason bees that live throughout the spring and summer. It’s also important to have houses where the cavities can be opened to check on the bees, and for doing an essential clean up in the fall.
Even though February’s weather has been a bit nasty this year, folks are already beginning to pick up their tubes of dormant mason bees at garden stores and other outlets. Many folks do this early to ensure they get their bees.
What is the best thing to do with them until it’s time to place them outside? Is it OK to store them in the fridge?
Hunter says fridge storage is fine, especially if you put the bee tubes in the crisper drawer where the humidity is far better. If you have settings on your fridge, set the dial between 2 and 3, not at 4 or 5. Cooler is better.
When should new mason bees be placed outside in their houses? According to Hunter, the bees that overwintered in your bee house will usually emerge about the end of April, depending upon the weather. Even if you have only a few bees, don’t set them out all at once.
“I do one third when the dandelions begin to open, one-third two weeks later, and the final one-third about mid-April. This will give you a better spread for pollination of your plants which, of course, open in sequence.”
What about the placement of the houses?
“They are fascinating insects, so put them where you can see them. The houses should sit about head height to keep raccoons and their friends from knocking them down, and morning sun is best. When they emerge, they will be a bit dozy as they warm up in the early-day sun, so maybe put a piece of fine mesh poultry wire, with a hole size no smaller than 2 cm, protruding like a canopy out from the house to prevent hungry birds enjoying a light snack.”
For further protection from the birds, especially those with long beaks, Hunter also recommends tucking the cocoons into a small Dixie cup behind the holes.
During this time, make sure not to use any chemicals on your lawn or in your garden, and if you can, encourage your neighbours to do the same. If the bees encounter chemicals, their numbers may be reduced because of to the non-natural smells. If all goes well, you can expect to double your numbers and colony the first year.
Mason bees are becoming more and more popular each year, and it’s wonderful that folks are now raising their own and growing colonies.
There are a few good resources out there for help, and I’m grateful to have Dave Hunter of Crown Bees as a coach to educate us about these incredible pollinators.
The easiest way to find more information about bees is to check online at the website crownbees.com, and look for BeeMail. Many people use BeeMail for ongoing information that is very helpful for those who want to establish and maintain a mason bee colony in their own backyards.
They are fascinating insects, so put them where you can see them. The houses should sit about head height.