Bumblebees are big and charismatic, beautiful and noticeable, and I think this is why they were one of the only groups of North American pollinators that a few early naturalists decided to count. Being big and fuzzy gets you counted! Because of this historical record, bumblebees were one of the first pollinator groups that could show that wild pollinators have been and still are in decline in North America. A 2019 study out of Michigan found that out of the 12 species studied, 6 had declined by more than 50% since the last century! The study is likely an indication of bumblebee population trends throughout the region, so now is the time to create a sanctuary for these sweet, chunky, wonderful bees. This is the first of a series of posts on bumblebee gardening that will cover what bumblebees need in spring, summer, fall, for nesting, and overwintering.
What the Queen Needs
There are 46 species of bumblebees in the United States, and most have a very similar way of life. From mid-March through June, queens emerge from little chambers underground, called hibernacula, and for the first couple weeks, the queens search for flowers in bloom and a nest site for her colony. Once queens find their nesting spot, usually under a clump of grass, or an abandoned mouse or chipmunk burrow, or cavities in dead trees, or in rock piles, they build a few little wax pots and start filling their pots up with nectar, while also making pollen balls which will provide the food for the first eggs. These eggs will be the first generation of worker bumblebees, essential workers to get the colony going. Founding the colony is likely the most precarious time for bumblebees because the queen is alone for about a month, foraging, incubating eggs, staying safe, feeding herself, waiting for her first brood of workers to come help.
And what this queen really needs (what she really needs!) from a gardener, are some early blooming flowers full of high quality pollen and nectar. Most bumblebee species won’t travel farther than ⅓ to ½ mile from their nests when foraging, so having good flowers close by is optimal -I can consult my own laziness to see that this is true. And, perhaps more importantly, there have been several studies in recent years indicating that a decline and absence of flowers or “floral resources” is a large factor in the worldwide decline of bumblebee populations. So, we got to plant some flowers.
Early Blooming Bumblebee Flowers
To help these beautiful, big, fuzzy bees, create space for a few (or loads and loads) of these early blooming, bumblebee approved, flowers in your yard. Many thanks to Dr. John Hilty of Illinois Wildflowers for the use of these wonderful photos and for maintaining his great online wildflower resource (each photo links to Illinois Wildflower’s botanical information).
You can find a printable list here:
And if you know of more early spring Bumblebee flowers, please let me know!
Wild Black Cherry
Serviceberry Amelanchier spp.
Peach leaf willow
Cream wild indigo
Wild blue phlox
Conserving Bumble Bees, Xerces Society for Invertebrate Conservation
Pollinator Plants, Midwest Region, Xerces Society for Invertebrate Conservation
Status of Pollinators in North America. National Research Council 2007. Washington, DC: The National Academies Press.
Patterns of widespread decline in North American Bumble Bees, Proceedings of the National Academy of Sciences
Gardening Plants for Early Pollinators, National Wildlife Federation
Woodland Phlox, Illinois Wildflowers
Strawberry Pollinators and Visitors: Focus on Bees, Manitoba Agriculture, Food and Rural Development
Conservation and Management of North American Bumblebees, USDA Forest Service
Bumblebees (Bombus spp.), David Inouye, University of Maryland, U.S. Forest Service
Bees, an Identification and Native Plant Forage Guide by Heather Holm
Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Goulson D, Nicholls E, Botías C, Rotheray EL (2015). Science347(6229):1255957
Declines in forage availability for bumblebees at a national scale. Carvell C, et al. (2006). Biol Conserv132(4):481–489
Macronutrient ratios in pollen shape bumble bee(Bombus impatiens) foraging strategies and floral preferences. Anthony D. Vaudoa,1, Harland M. Patcha, David A. Mortensenb, John F. Tookera, and Christina M. Grozingera
Bumblebees of Wisconsin, Life Cycle and Biology, University of Wisconsin