Supporting Native Bees at the Rain Garden

Updated: Mar 12, 2021

Just in time for World Bee Day on May 20th, SOS has installed a pair of nesting shelters for wild, native bees at the Niakwa Trail Demonstration Rain Garden.

A native unarmed leafcutter bee
A native leafcutter bee, found along the Seine

In contrast to the typical image of a bustling honeybee hive, the majority of our native bee species live solitary lives, with each female provisioning her own individual nest. They also do not produce honey! Instead, many bee species fashion small balls of "bee bread," a mixture of nectar and pollen, with which they feed their developing brood.

The newly installed nesting shelters, or "bee houses," provide nesting opportunities for tunnel-nesting bees. The majority of native bees are actually ground-nesting bees; this includes familiar bumble bees, which typically make use of abandoned rodent burrows. But tunnel-nesting bees are easier to provide managed shelter for, as they nest inside preexisting tunnel structures such as hollow plant stems or tree branches.

The block is set back for protection from the rain
The "bee block" is set back for protection from the rain

There are many commercially-available native bee houses these days, but many of the designs can do more harm than good, particularly if not properly managed. The safest approach for the bees is to drill holes into a solid block of wood, so long as the holes are at least 6 inches deep and are lined with paper. The block may be re-used, but requires annual maintenance comprised of cleaning with a bleach solution to prevent the spread of fungus and disease and re-lining with fresh paper. The holes in the block must be enclosed at the back, and the house should be securely mounted with east or south-east sun exposure.

The Rain Garden is a great location for native bee houses, as it lacks natural nesting sites yet is abundant in everything else that bees need to thrive. The native flowers provide nectar and pollen, there is plenty of sunshine for the bees to warm themselves, and the water draining from the adjacent parking lot produces muddy areas needed by mason bees for their nests.

We will have to wait and see if the Rain Garden bee houses succeed in attracting bees from the area. If they do, the paper liners, along with their resident dormant bees, will be removed in the fall. The bee-filled liners will be placed in a protected outdoor area where the dormant bees will spend the winter, and they will be released the following spring.

If you would like to learn more about our native bees and how to support them, some helpful resources are Bee Better Manitoba and the Xerces Society.