Pollination with Mason Bees
In simplest terms, pollination is the movement of pollen from one flower to another, resulting in fertilization and, ultimately, fruiting by the receiving plant. Without pollination, there wouldn’t be plant propagation—the increasing in number and location of individuals of a plant species. And, since nearly all animals, including human beings, ultimately rely on plants for food, eventually there would be no food supply.
Among the most effective pollinators—vectors for pollen’s travel from one plant to another—are insects. And the real stars of the insect-pollinator world are bees. For centuries, farmers and orchardists relied on the honeybee for pollination, cultivating these bees not mainly for honey but for the pollination services they provide.
Overlooked is another bee that can be domesticated for pollination purposes, the blue orchard or mason bee. These solitary bees do not hive together, do not attack perceived threateners (including people), and live only two to six weeks.
As pollinators, though, mason bees are quiet heroes because they hatch out in early spring, long before most other insect pollinators are active. This means that, in a cool-spring climate like the Maritime Northwest’s, you can rely on them to pollinate early-blossoming crops when other pollinators can’t. (Pear trees, for example, blossom early here and can prove frustrating to get pollinated.)
“Keeping” mason bees involves the lowest-maintenance relationship you may ever have. You can buy cocoons online or in a nursery (avoiding disreputable sources to prevent the spread of parasites) and set them out in early spring when daytime temps are reliably in the 50’s Fahrenheit.
The bees will hatch and mate quickly. Females will visit flowers for pollen and nectar to make a “loaf” of food for their future offspring and deposit it in a crevice or hole they’ve found. Then they lay their eggs on this provision before walling off the egg-plus-food bundle with mud they gather and transport for this purpose. They repeat the process, resulting in a horizontal stack of egg chambers.
If you want to keep mason bees for more than one season, you can put out in spring a nesting block or tubes (available online or in stores) where bees can lay eggs, and from which you can harvest next year’s cocoons. By mid-summer, your bee housing is full, and you should store it safely away from parasites and birds. In early fall, you open the housing, gather the now-developed bee cocoons and store them over the winter in the fridge. The following spring, you put out the cocoons, repeating the cycle. Your yield of bees grows year over year.
Beyond their use in helping pollinate food crops, mason bees participate in the far larger activity of pollinating native plants. They’re ultimately just a reminder of how landowners need to provide or protect plants that offer pollinators an opportunity to flourish so that they can then provide food and habitat for the rest of us.
