Mason Bees in the Garden

With the decline of honey bee populations in recent years, the hunt has been on for alternative pollinators. Orchard mason bees are earning high marks for their ability to pollinate fruit trees, flowers, and vegetables.

Orchard mason bees don’t live in hives. Instead, they nest in hollow areas, such as holes made by woodpeckers and insects. You can buy nesting boxes to attract mason bees, or make one by drilling holes in a wooden box (wood should be untreated). Plans for different types of boxes can be found online. Here are just a couple of the helpful sites I found: North Carolina State University Extension Service at http://www.ces.ncsu.edu/depts/ent/notes/Other/note109/note109.html and Washington State University Extension Service at http://gardening.wsu.edu/library/inse006/inse006.htm.

Interestingly, hollowed-out spaces are favorable sites for orchard mason bees because of the way females lay their eggs. After gathering a bit of pollen, a female places the pollen at the bottom (or back) of the hole. Next, she lays an egg on top of the pollen and creates a partition with mud before repeating the cycle—pollen, egg, mud, pollen, egg, mud—until she gets to the opening of the hole and covers the end with one last dab of mud.

Because these bees tend to forage within 100 yards of their nest, once you’ve attracted them to your garden you can expect good pollination. Better still, orchard mason bees are much less aggressive than other bees, so there is a lower risk of being stung. The only real downside is that they don’t make honey.

If anyone decides to give these a try, or already has experience with orchard mason bees, please send a note and tell the rest of us about them.