Bumblebees (Bombus) are large, fuzzy insects that are highly efficient pollinators. Their distinctive size and rapid wing movement allow them to perform “buzz pollination,” a specialized technique where they vibrate flowers to release otherwise inaccessible pollen. This ability makes them valuable for the production of many fruits and vegetables, including tomatoes, blueberries, and peppers. Welcoming these foragers into a garden supports both local plant diversity and food production.
Sensory Cues Bumblebees Use to Find Flowers
Bumblebees rely on a combination of sight and smell to navigate the floral landscape. Their vision differs significantly from human sight, as they can perceive ultraviolet (UV) light. Many flowers display distinct UV patterns, known as nectar guides, that serve as visual beacons directing the bee toward the pollen and nectar sources at the flower’s center. This specialized vision aids them in optimizing their foraging routes and finding rewarding blooms quickly.
The bumblebee’s sense of smell is also exceptionally acute. Flowers release a complex mixture of airborne chemicals called volatile organic compounds (VOCs) that act as a fragrant advertisement. As a bee approaches a flower, the scent pattern often becomes more important than color for pinpointing the exact location of the reward. Research suggests that bees can detect the subtle electrical charge difference between themselves and a flower, which may signal whether the flower has recently been visited.
Essential Flower Characteristics for Pollination
The physical structure of a flower is a major factor in its attractiveness to a bumblebee. Flowers with deep corollas or tubular shapes often require the bee’s long tongue to reach the nectar, funneling the bee into a position for optimal pollen transfer. The size and shape of the flower must also be compatible with the bee’s body size, offering a stable landing platform or a structure that can be easily grasped during foraging. Successful pollination hinges on the plant providing an accessible and generous reward.
Flowers that offer high-quality and abundant pollen and nectar are preferentially visited. Native plants are superior to highly cultivated hybrid varieties because many hybrids have been bred for features like unusual colors or large, double layers of petals. These modifications often reduce nectar content or make the reward inaccessible. Modified flowers frequently lack the necessary pollen quantity or nutritional quality that bumblebees require for their colony’s development. Selecting single-petal flowers, which have open centers, ensures the pollen and nectar are readily available.
Specific Plant Recommendations for Bumblebee Gardens
The most effective garden design incorporates a variety of plants that are rich sources of both nectar and pollen. Perennial favorites include Bee Balm (Monarda didyma), which has specialized tubular flowers perfect for the long tongues of many bumblebee species. Lavender (Lavandula) is another excellent perennial choice, offering dense spikes of small, nectar-rich flowers that bloom over a long period. Gardeners can also plant shrubs like Blueberry (Vaccinium species), which provide an early spring pollen source when other flowers are scarce.
Annuals and herbs are also highly attractive and offer continuous blooms throughout the season. Sunflowers (Helianthus) provide a large amount of pollen on their open faces. Borage (Borago officinalis) is a robust herb with star-shaped blue flowers that consistently offer a high yield of nectar. Herbs such as Catnip (Nepeta cataria) and various types of Clover (Trifolium) are simple to grow and are heavily favored by bumblebees for their consistent food supply.
Establishing a Continuous Bloom Cycle
A successful bumblebee garden provides a steady food supply from spring until autumn. This requires “succession planting,” which involves selecting a range of plants that bloom at different times of the year, ensuring flowers are always available. Early-blooming Crocus or Lungwort can be followed by mid-season flowers like Coneflower, and then late-season blooms such as Asters or Goldenrod. This staggered approach sustains the bee colony throughout its life cycle.
Planting flowers in large clusters, or “mass planting,” significantly increases foraging efficiency. A large patch of a single flower type is more visually striking and offers a denser reward, allowing the bees to collect more resources with less energy expenditure. Maintaining a healthy habitat involves avoiding systemic pesticides that can harm bees and providing shallow water sources, such as a saucer of water with small stones for landing. These steps create a safe and efficient foraging environment, encouraging bumblebees to make the garden a regular stop.