Mason Bees: The Stars of Strawberry Season

Sweet, succulent strawberries are in season at Southall for the next few weeks, and the patch is buzzing with hundreds of new workers brought in to help ensure we make the most of the first fruits to ripen in middle Tennessee. Recruited last spring, these laborers have been waiting all winter for this moment, and now they’re crawling out of their pea-sized cocoons.

Native mason bees are awakening from hibernation to produce their annual offspring, a process that happens to make them ideal strawberry pollinators. June-bearing berry crowns (Chandler, Sweet Charlie, and Jewel varieties) were planted last fall, with crimson clover seeded on either side of the rows – all timed to work together right now.

Also called blue orchard bees thanks to their unique coloration and the results they’ve delivered for years in the apple orchards of the Pacific Northwest, curious growers around the country have begun to experiment with mason bees on other crops. At Southall, Pollination Program Manager Jay Williams saw an opportunity to develop our own fleet of masons from the natives already living on the farm.

Nearly everything is different about the process, when compared to raising honeybees. Aside from looking different, with their iridescent blue bodies, mason bees live in individual homes—each with its own queen, yet still as part of a community. Williams constructs mason bee houses from natural reed tubes that replicate the holes found in nature. Among the 200 tubes in a mason bee house, each queen will raise several offspring over the course of about eight weeks, sealing each egg with a cap of mud after leaving the young with a ball of pollen and nectar to live on when it hatches into a pupa. Williams harvests the capped reeds in the fall, when each bee has matured into its own cocoon inside the reed, and then holds them dormant in the refrigerator until needed. When the cultivation team sees new blooms on the strawberries, fresh cocoons are set out in the row houses and hatch within 24 hours, a steady supply of reinforcement pollinators.

Whereas honeybees wake up slowly and labor through the hot months, mason bees emerge early with a sole focus on mating and laying next year’s eggs. They don’t mind working in cooler weather, even in the rain, to get the job done. With strawberries setting flowers in early April and peaking in June, the timing couldn’t be more perfect. As the weather warms up, a range of pollinators are attracted to the natural fence of crimson clover. The cover crop not only fixes nitrogen in the soil, but its bloom spires are full of nectar that ends up flavoring Southall’s honey.

Mason bees only fly a few hundred feet from home, unlike honeybees, who can range for miles in search of nectar. An added bonus: they almost never sting.

And from a pollination standpoint, their body structure means that masons gather pollen on their trunks versus their legs, and their clumsy flight makes them “belly flop” into flowers, slinging pollen far and wide. All of these factors are boons for strawberry production.

“Like much of what we do in agriculture at Southall, this is an experiment,” Brown said. “But what we’ve seen in the early harvest this year is not only more strawberries per plant, but larger ones. That’s what we anticipated, and now we can continue to refine our processes in terms of timing and placement of the mason bee houses.”

For Williams, who developed a property-wide pollination plan utilizing advanced technology for the Southall apiary that he’s grown to include more than 4.5 million bees, the natives are a new tool in the pollination toolbox.

“We’re now working with native leaf cutter bees in the orchard and summer production fields, with mason bees in the strawberries, and we’ve seen what honeybees can do with warm-season crops over the course of a few years now,” he says. “It constantly amazes me how nature provides these resources –just like humans, if we give them the support and put them in a position to be successful, they will deliver more than we could have ever imagined in return.”

The reward is not simply in the yield, they say, but in bearing witness to the process. We hope to see you in the berry patch next spring.