Hollyhocks (Alcea rosea) are tall, cottage garden favorites that produce striking spires of flowers throughout the summer months. Hollyhocks are highly effective and reliable bee attractors. Their large, open blooms serve as a significant source of both nectar and pollen, making them a popular foraging stop for various species of pollinators.
The Biological Appeal to Bees
The large, cup-shaped corolla provides a broad landing platform, which is particularly useful for larger bees to navigate and land comfortably. This open structure allows for relatively easy access to the plant’s rewards.
At the base of the flower are five nectaries located on the sepals, which produce sweet liquid for the visiting insects. Bees must reach deep into the flower, often nuzzling between the petals, to access this abundant nectar supply. This foraging behavior ensures that the bee’s body makes contact with the male reproductive structures.
Hollyhocks also provide a substantial pollen reward, which is a primary protein source for bees. The pollen grains possess a prickly outer surface, or exine, specifically adapted to adhere effectively to the hairy bodies of bees as they maneuver inside the flower.
Specific Bee Visitors
Bumblebees (Bombus species) are among the most frequent and efficient visitors to hollyhocks, often spending extended time foraging or even sleeping overnight inside the cup-shaped bloom. Solitary bees, such as longhorn bees (Melissodes) and green metallic sweat bees (Agapostemon), are also common visitors.
The plant’s structure provides a sturdy substrate for foraging, as the tuft of styles and stamens in the center offers a foothold for the bees to collect resources. While honeybees are generalist foragers, they tend to favor large, dense plantings of the same flower type, meaning they may be less prevalent on small hollyhock groupings than native bumblebees are.
Gardening for Pollinators
To maximize bee attraction, the selection of hollyhock variety is important. Single-petal varieties, which most closely resemble the original wild species, are significantly more effective at attracting pollinators than double-petal cultivars. Extra petals in double-flowered types can physically obstruct access to the nectar and pollen resources at the flower’s center.
Opting for single-flowered types ensures that the nectaries and the pollen-laden anthers remain fully accessible to foraging insects. Bumblebees appear to show a preference for lighter colors, such as white or pink petals, although the full spectrum of colors attracts various pollinators.
Placement is also a factor, as hollyhocks thrive in full sun, which is where bees are most actively foraging. Planting hollyhocks in groups and allowing them to self-seed can help establish a continuous, reliable food source throughout the summer season. While they are often biennials, their prolific self-seeding nature means a continuous cycle of bloom is maintained in the garden year after year.