Bumble bees are important pollinators for home gardens and small farms. Their fuzzy bodies allow them to work in cold and wet conditions that keep honey bees in the hive. By providing suitable habitats for bumble bees, gardeners can increase the pollination services these beneficial insects provide. This article explores strategies for attracting and supporting healthy bumble bee colonies to maximize their pollination contributions.
Why Bumble Bees are Valuable Pollinators
There are over 40 species of bumble bees native to North America. These furry insects form small colonies each spring when new queens emerge from hibernation. The queens gather nectar and pollen to provision the first eggs. As the colony grows through summer, worker bees take over foraging duties. Bumble bees are generalist pollinators that visit a wide variety of flowering plants.
Bumble bees have several advantages as pollinators:
- They forage at cooler temperatures and lower light levels than honey bees. Bumble bees will work earlier and later in the day and can fly in light rain.
- Their fuzzy bodies easily pick up and carry pollen from flower to flower.
- Bumble bees perform “buzz pollination” by grabbing the flower in their jaws and vibrating their wing muscles. This dislodges pollen that is difficult for other bees to access.
- Native bumble bees have evolved close relationships with many local plant species. Their activity triggers fruit and seed production for tomatoes, peppers, blueberries and other crops.
By supporting bumble bee populations, gardeners can easily tap into excellent free pollination services. Healthy bumble bee activity increases yields and quality for many common garden plants.
Providing Foraging Habitat
Bumble bees have different nutritional needs than honey bees. They cannot store large reserves of honey, so require a constant source of nectar and pollen throughout the colony’s active months. The key to attracting bumble bees is providing season-long blooms of their favorite flowers.
Include early spring blooms like crocuses, hepatica and hyacinths. Dandelions, clover and violets provide valuable nutrients as bumble bee colonies are growing. Summer staples include catmint, lavender, cosmos, sunflowers and bee balm. Late-flowering zinnias, asters, sedums and goldenrod sustain bees into fall.
Be sure to include native plants matched to your ecoregion. Check with local native plant societies or conservation groups for recommendations. Non-native flowers may provide nectar, but native plants usually have the best pollen quality.
Focus on clump-forming and flowering shrubs rather than thallose groundcovers. Bumble bees need landing pads as they move between flowers. Leave some areas of bare soil exposed for ground-nesting bumble bees. Avoid using thick mulches that can prevent bees from digging nests.
Providing Nesting Habitat
Bumble bees usually nest in small cavities such as abandoned rodent burrows. Providing suitable nest sites is the other key factor in supporting bumble bee populations. Site selection influences the survival of new queens through winter.
Leave areas of unmowed, unmulched ground in sunny spots protected from flooding.Brush piles, rock walls and hedgerows also provide potential nesting habitat. Some bees will nest above ground in old bird nests or grass tussocks. Native bunch grasses make good nesting substrate.
Commercial bumble bee boxes are available, but success rates are mixed. It is difficult to mimic the insulating properties of an underground nest. Placing boxes in sheds or garages may work better than exposed outdoor locations. Ensure boxes are cleaned and fresh each spring so bees don’t encounter old pathogens.
A healthy population of ground-nesting bumble bees may occupy the available habitat without needing boxes. Focus first on providing the right mix of flowers, nesting materials and safe overwintering sites.
Protecting Overwintering Queens
New bumble bee colonies each spring depend on mated queens surviving the winter. These queens emerge in late summer or fall, mate, then dig into leaf litter or burrow into soft soil. Suitable winter shelter sites may limit queen survival more than the cold itself.
To support the queens, refrain from disrupting potential nesting sites during the fall. Allow fallen leaves, brush piles, and unmown sections to remain, as queens may use them for nesting. Add a layer of leaves or pine needle mulch to flower beds and around trees for added insulation. Woodpiles, rocks, and garden debris can all serve as shelters for overwintering queens.
Reducing Threats from Disease, Pesticides and Climate Change
Unfortunately, many bumble bee species are in decline from habitat loss, imported diseases, pesticides and climate change. Home gardeners can make a difference by reducing these threats.
Avoid transporting commercial bumble bees beyond their native ranges. Imported bees have spread lethal pathogens to which native bumble bees have no immunity. Always buy regionally-sourced bees or plants. Inspect purchased plants for hitch-hiking bees before bringing home.
When needed, use organic insecticides that have low toxicity to bees. Avoid spraying open flowers where bees are actively foraging. Always read and follow pesticide labels carefully. Consider treating only affected plants instead of broadcasting sprays over entire areas. Tolerate minor pest damage to support bee populations.
To assist bees in coping with the summer heat and drought, offer a water source such as a shallow bird bath, a waterfall, or a mister. Fill bee blocks or ceramic pots with damp sand to create cool underground havens. Plant heat-resistant flowering annuals to ensure continuous bloom availability. Ensure there’s sufficient habitat connectivity, allowing bees to migrate to areas with more favorable conditions.
Every landscape, no matter how small, can benefit bumble bees. By understanding their habitat needs and life cycle, gardeners can take meaningful actions to attract and support these essential pollinators. A diverse community of native bees improves productivity of fruiting plants and ensures balanced ecosystems. With supportive habitats, bumble bees will handsomely reward the gardener’s efforts with bountiful harvests.
Every landscape, no matter how small, can benefit bumble bees. By understanding their habitat needs and life cycle, gardeners can take meaningful actions to attract and support these essential pollinators. A diverse community of native bees improves productivity of fruiting plants and ensures balanced ecosystems. With supportive habitats, bumble bees will handsomely reward the gardener’s efforts with bountiful harvests.
Specific Plants to Attract Bumble Bees
When selecting plants for your bumble bee garden, aim for continuous bloom throughout spring, summer and fall. Use mostly native perennials, which are adapted to local soils and provide the best pollen and nectar. Here are some top plant choices to attract and nourish bumble bees in each season:
Spring Blooms
- Crocuses – Early bulbs provide needed nectar.
- Wild lilac – Fragrant spring-blooming shrub.
- Redbud – Small native tree with abundant pink flowers.
- Wild geranium – Low-growing woodland perennial.
- Blue-eyed Mary – Reseeds readily in sunny meadows.
- Columbine – Native columbine attracts many pollinators.
- Trilliums – Woodland wildflowers bloom early.
Summer Blossoms
- Bee balm – A favorite of bees; mint family member.
- Cosmos – Prolific annuals bloom all summer.
- Coreopsis – Cheerful daisy-like perennials.
- Lavender – Fragrant purple flowers bees love.
- Sunflowers – Native annuals provide pollen and nectar.
- Milkweed – Essential monarch host; flowers attract bees.
- Herbs – Basil, oregano, thyme all draw bees.
Fall Feeding
- Goldenrod – Important native season extender.
- Aster – Abundant late wildflowers feed bees well.
- Sedum – Succulent perennials flower until frost.
- Joe-pye weed – Tall wildflower supports late bees.
- Helenium – Daisy relative blooms late.
- Russian sage – Blue flowers late into fall.
- Winterberry – Bees take advantage of late shrub flowers.
Focus on planting successive waves of long-blooming flowers. Avoid modern hybrids; choose old-fashioned heirlooms for the best bee benefits. Always leave areas of undisturbed ground for nesting sites. With plentiful food and shelter, your garden will soon be buzzing with active bumble bees.
