Bumble Bees—The Essential, Indefatigable Pollinators - Brooklyn Botanic Garden (2024)

On hot, lazy summer days I like to go out in my garden, flop down on the old chaise lounge, sip a margarita, and watch pollinators at work on my flowers. Butterflies are the divas of these botanical love fests, captivating with their flamboyant colors, stripes, and spots as they flit from bloom to bloom. Hummingbirds are the acrobats, zipping up, down, sideways, and even backwards to probe long-throated, ruby-colored blossoms. Bumble bees are the workaholics—diligent and dependable, but a little dorky as they lumber around the garden.

The bumble bee isn't the most glamorous insect around, but the lovable bear of a bee surpasses even the celebrated honey bee in the industriousnessdepartment. Bumble bees are often up and out of the hive before dawn, way before the honeybees, and they're frequently still hard at work after the sun has set.In fact, the bumble bee is one of the world's most proficient practitioners of the pollinating arts. Its distinctive striped fur coat is tailor-made for attracting pollen, and the plump pollinator is built like a Mack truck to carry a lot of cargo.

We live on a planet pollinated primarily by bees. Bees fertilize most of our favorite flowers, and pollinate a third of the plants we eat. Bumble bees are important pollinators of tomatoes, eggplants, peppers, melons, raspberries, blueberries, cranberries, strawberries, and many other crops, and are the only known pollinators of potatoes worldwide. They are also the exclusive pollinator of several rare and imperiled wildflowers, including native monkshoods and lady's tresses orchids. Without these essential insects, farm productivity would plummet and wildflowers would become extinct. In short, bumblebees and other bees are essential for our own well being and the survival of a good deal of the world's biodiversity.

But bees are in trouble. In recent years, parasitic mites have killed most feral honeybees and many colonies maintained by beekeepers. Meanwhile, the natural habitats of bumble bees and other native bees, which were pollinating North America long before the colonists arrived with their European honeybees, continue to be carved up, destroyed, or degraded. However, we all can help improve the lot of bumble bees by planting the flowers they love, whether we garden on an acre or in a window box. One small bumble bee garden may not seem like much, but as these patches of backyard habitat multiply across the community and the country, they can play a vital role in feeding and protecting threatened pollinators.

My Shelter Island, New York, garden is jam-packed with monkshoods and otherbumble bee magnets. I grow them in my wildflower border, in a tiny meadow I'veplanted for pollinators, in pots on my patio, and in the shady woodlands thatsurround my house. All season long, my yard is buzzing as the chubby bees workthe blossoms.

I also plant lots of the blue, purple, white, and yellow flowers that bumble bees love best. In order to provide a steady food supply, I try to have some of their favorite flowers blooming from spring through fall, when they are active. I garden mostly with native wildflowers that evolved in this area, because they are best adapted to the local soils and climate—and the localpollinators. And I never use insecticides, which harm bees and other beneficialbugs. If a garden plant can't survive without poisonous chemicals, I figureit's not worth growing.

Bees are not only the workaholics of the insect world but also the cupids ofthe plant world. As they buzz along from flower to flower, collecting food forthe baby bees back at the hive, they're also facilitating plant reproduction.Botanist Peter Bernhardt, author of The Rose's Kiss, calls them "aflower's winged penis."

Plant sex differs from human sex in that it typically must be consummated bya third party, whether the wind, a hummingbird, or a bumble bee that transferspollen from one blossom to another. To lure bumble bees and otherintermediaries, plants clad themselves in colorful flowers with seductivescents. While the bee is fertilizing the flower, the plant is returning thefavor, offering nectar, the insect equivalent of soda pop, and/or life-givingprotein in the form of pollen.

Some flowers are especially suited for pollination by bumble bees, havingevolved a number of characteristics suited to the creature's girth, behavior,and other attributes. Unlike humans, bees can see ultraviolet; many of theflowers we see as white, they see as ultraviolet. They not only see this colorbut also are attracted to it, making a beeline to flowers in the ultravioletsas well as the blues and purples that dominate one end of the color spectrum,though they're attracted to yellow blossoms, too. Many of these flowers havebizarre wavy lines or leopard-like spots on their petals that serve assignposts pointing the bees toward the nectaries, where nectar is produced andthe insects can satisfy their serious sweet tooth.

Many bumble bees are so-called long-tongued species with a lengthy,tube-shaped schnozzola called a proboscis that holds the tongue. They use thisapparatus to probe the deep recesses of elongated blooms and suck up nectar.Not surprisingly, the petals of bumble bee flowers often form elegant, elongatedbells, funnels, or tubes, with the nectaries hidden deep inside. In somespecies, the nectar is hidden at the end of a long, hollow floral structurecalled a spur. In these ways, the plants make sure that the precious liquidgets only to the bumble bee, the animal most capable of accomplishingpollination.

The attribute for which the bumble bee is best known, apart from itsluxurious striped pelt, is probably its heft. The flowers that cater to thisplus-size pollinator must be robust, because, unlike the acrobatic hummingbird,the bumble bee has to perch on or cling to them in order to sip nectar andcollect pollen. That is why the blooms of many snapdragons, mints, orchids,peas, and other flowers have modified lower petals—lips, aprons, orkeels—that serve as sturdy landing pads. Moreover, bumble bee blossomsoften come equipped with some form of physical barrier that only the bulkyinsect can surmount. For example, in the flowers of many members of the peafamily, the nectaries, along with the sexual organs, are enclosed in the twolowermost petals that are joined together to form the keel. When a bumble beelands on the keel, its weight forces the petals to pop open, exposing theflower's private parts.

No blossoms are more beautifully adapted to pollination by bumble bees than the monkshoods (Aconitum species)—in fact, they depend entirely onbumble bees for pollination. As the name suggests, the petal-like upper sepals of a monkshood flower form a large, erect, helmet-shaped hood, which concealstwo long spurs with huge nectaries at the end reachable only by long-tongued bumble bees. A bumble bee visiting an Aconitum lands on the lower sepals.As it heads towards the nectaries hidden in the hood, it clambers over the maleand female parts of the flower and is dusted with pollen. When it flies off tothe next monkshood blossom and deposits some of this pollen, the bee completesits part in the continuation of the species.

In spring, my Shelter Island woodland garden is a wash of pastel purple whenthe violets, bumble bee favorites, bloom among glades of fern I've planted alongpaths and around the house. One side of my patio brushes up against the meadow,which is abuzz with bees in June when the blue wild lupine blooms. The bees arewild about the tall purple spires of blazing stars that bloom in summer. FromSeptember until late October or early November native asters and goldenrods arethe main attractions. On the other side of the patio, my pollinator gardencontinues in a dampish area. Here is a border of wetland bloomers laden withbees (and butterflies) for weeks in summer, including joe pye weed, with hugedomed heads of dusty mauve flowers on eight-foot stems, and sweet pepperbush,with fragrant spikes of white flowers.

Although native wildflowers are the most reliable sources of bee food, I dogrow some traditional garden flowers and herbs in big old galvanized tubs onthe patio, and the neighboring bumble bees don't seem to mind a bit. They areespecially fond of fragrant white or purple heliotrope and herbs like borage,whose star-shaped, fuzzy blooms are the color of the sky on a perfect June day.I choose classic single-flowered varieties of old-fashioned cottage gardenplants such as snapdragons, avoiding the newfangled cultivars with doubleblossoms. Breeders typically have size, shape, or color in mind when theycreate these varieties, not the most nutritious pollen or maximum nectarproduction so important to bees. In the words of entomologist and beespecialist Stephen Buchman, these plants "are often all show and no bee chow."For example, while old-fashioned single larkspurs are a favored source of sweetnectar for long-tongued bumble bees, varieties with double flowers lack the spurfor which the plant is named, as well as the nectar stored in it. Likewise,bumble bees straddle the small flowers of violets to sip nectar, but they can'tmanage the much bigger blossoms of pansies, their more cultivated cousins.

Often, it isn't a lack of flowers that limits native bees but rather realestate. This isn't a problem in my mostly wild garden, but the manicured turfand flowerbeds of suburbia offer few suitable nesting sites for social bees like bumble bees. Old mouse nests or rodent burrows are the preferred abodes, but bumble bee hives have also been found in deserted bird nests, rubbish piles, and thick, cushioned clumps of moss. If there are no abandoned bird nests or rubbish piles in your yard, you can buy a prefabricated bumble bee nest box. One example is the Humble Bumble Home, offered by a Washington-based, family-ownedbusiness called Knox Cellars (www.knoxcellars.com). It consists of a pine box, soft cotton nesting material, an instruction book on the life history of the bumble bee, and a clear plastic "ceiling" that allows you to lift the box's wooden roof and observe the busy bees at work. I haven't tried one, but Ihear that bumble bees do take up residence in such structures, whether pre-fab or homemade.

Creating a healthy habitat for bumble bees does not require great horticultural talent. These are not shy, finicky creatures. You don't have tore-landscape your entire property; just tuck favorite bumble bee blooms between your existing plants, or grow them in pots where you can observe the insects up close. Then sit back with a long, cool drink and enjoy the show.