Most native plant gardeners do what they do, at least in part, to help pollinators. With important bee populations in steep decline as a result of disappearing food sources, this is often an area of emphasis for our own gardens.
But for some the dominant image of bees is still the imported honeybee pollinating crops in a sunny agricultural field. The wide variety of native bees, on the other hand, have certain environmental preferences, and many gardeners wonder if they still benefit from a shade garden.
We think of bees as thriving in the sun and visiting flowers in prairie and meadow gardens; what if a large part of your property is part or full shade due to tree cover?
Do Bees Live in the Forest and Feed on Shade Plants?
This is an important question given that so much of the United States was heavily forested before European colonization. It would make sense that if shade conditions occupied the majority of land, many native bees have evolved to thrive there.
Overall, it is true that most bees prefer sunny meadows but shade gardens can still support quite a few of them.
Some benefit from shade for a portion of their life cycle and many even spend the entirety of their lives in shady conditions.
As one article put it, “forested ecosystems offer forage and a place to make nests or hibernate. A variety of understory forbs and woody shrubs as well as some broadleaf trees provide nectar and pollen.”
An issue complicating this question is the fact that historically there has been a dearth of research on native bees, and it turns out that there has been even less research done on those which inhabit forested ecosystems.
But there are some studies we can turn to to get more guidance on native bees in shade for use in our own gardens.
What Does the Research Say About Wild Bees and Shade?
Research conducted in New Jersey, Pennsylvania and New York found that “the total number of bee species—and likewise the total number of individual bees—was roughly the same in landscapes that were largely forested as they were in deforested landscapes dominated by agriculture or suburban development.”
Putting more numbers to it, “thirty-eight out of 118 species were forest associated.”
Other studies have said that 1/3 of our native bees rely on forested habitats for their whole life cycle, and another 1/3 of species for part of their lives.
These shade associated bees were most likely to be active in the spring.
Which Native Bees Like and Benefit from Shade?
The book Victory Gardens for Bees gives some information on a couple shade-associated bee species and ideal native plants to have in your home garden: “Blue orchard mason bees and bumblebees have the ability to forage in lower temperatures and are more likely to seek nectar and pollen in shade. Plants with long nectar spurs, such as lungwort, Dutchman’s breeches and wild columbine” are good examples.”
The author also extols the benefits of not just the plants you have but also other gardening practices: “Shade gardens are also the ideal setting for rotting stumps that provide nesting sites and fungal benefits for bees and serve as hibernacula for bumblebee queens that have gorged on nectar from fall flowers.”
Others nest in leaf litter on the forest floor, which you can easily replicate in a shady area of the yard by leaving the leaves instead of raking them all away, which also benefits your garden by acting as a native mulch and improving your soil.
Returning to the research from the previous section, the study goes on to identify the most common forest-associated bees, pointing out that the species come from only a few genera:
Andrena (mining bees), Nomada (brood parasites of mining bees), Colletes (plasterer bees), Osmia (mason bees), Bombus (bumble bees), and Lasioglossum (sweat bees).
A majority of these forest bees are solitary and short-lived and their activity corresponds to April and May when spring ephemerals are in bloom. Being solitary means each female builds a nest, lays eggs, and dies soon after. These bees are typically gone by June.
Planting more of this type of early-blooming plant, which might include, trillium, bluebells, woodland phlox, golden alexanders in addition to the plants mentioned above, will do a world of good for these native bees.
A smaller percentage of bees, including the Bombus and Lasioglossum genera, are social bees, which means they form colonies where more than one generation live through the spring and summer months.
Overall, ensuring your garden has plants that bloom in all seasons is an excellent way to benefit all types of native bees, from the shade-loving to those that thrive in the sun.
Note: Much of this information including the New Jersey study relates to Eastern temperate forests on the East Coast and in the Midwest, but similar trends are found in disparate ecoregions as well, such as the Pacific Northwest as explained in this article.
The following webinar goes into more details about this and related research:
Leave a Reply