The climbing vine Clematis is a popular garden fixture, known for its extensive flowering and dramatic vertical presence. The question of whether it attracts bees has a nuanced answer. While many varieties are visited by foraging bees, the level of attraction and the nutritional reward depend heavily on the specific flower structure and species chosen. Understanding the flower’s biology and the bee’s foraging needs is necessary to maximize the vine’s benefit to local pollinator populations.
Understanding the Mechanism of Pollinator Attraction
Bees visit flowers primarily to collect pollen, which provides protein for their developing larvae, and nectar, a sugar-rich solution that fuels their flight. The physical architecture of a Clematis bloom directly influences the accessibility and availability of these resources. For a flower to be an effective bee forage, its reproductive parts must be exposed or easily reachable by the insect.
Many Clematis species feature numerous stamens. This abundance of stamens makes pollen the primary resource offered by many Clematis varieties, especially those with an open, star-like shape. The concentration and easy access of pollen make these flowers highly appealing to generalist bee species, such as honeybees and bumblebees. However, some deep, bell-shaped or tubular flowers may restrict access to the nectar at the base, limiting their appeal to bees with shorter tongues.
The flower’s shape determines which species of bee can successfully forage. Open, bowl-shaped flowers allow easy access for short-tongued bees to collect pollen by walking across the exposed stamens. Conversely, varieties with a nodding, bell-like structure may only be effectively foraged by long-tongued bees, which can reach nectar deeper inside. The simple, un-doubled structure of species types ensures that both pollen and nectar, if present, are visible and straightforward to collect.
Clematis Varieties: Which Flowers Attract Bees Most Effectively
Bee attraction depends significantly on the distinction between the highly cultivated, large-flowered hybrids and the smaller, more natural species varieties. Modern large-flowered ornamental hybrids, such as ‘Nelly Moser’ or ‘The President,’ often have “doubled” flowers, meaning their stamens have been bred into extra decorative petals. This genetic modification significantly reduces the amount of pollen or nectar produced, rendering them poor food sources for foraging insects.
By contrast, smaller-flowered Clematis species are superior for attracting bees because their flowers retain a simpler, natural structure. Species like Clematis tangutica, which produces nodding yellow lanterns, and Clematis viticella, are known for providing substantial amounts of pollen. These species are excellent contributors to a pollinator garden because their resources are readily available.
Specific varieties, such as the late-flowering Clematis rehderiana, are particularly attractive to bumblebees, which value its abundant late-season pollen. Similarly, the winter-flowering Clematis cirrhosa varieties, like ‘Freckles,’ offer a valuable early-season pollen source when few other plants are blooming. Prioritizing these species ensures the flower is a functional food source, not just an aesthetic one.
Clematis as a Resource for Other Garden Pollinators
While bees are the primary visitors, Clematis vines also serve as a resource for other garden pollinators. Hoverflies, which are effective pollinators, are frequently observed feeding on pollen on the exposed stamens of open-faced Clematis flowers.
Some native species, like Clematis virginiana (Virgin’s Bower), are known to be pollinator magnets, attracting a range of insects including various wasps and small native bees. Butterflies may occasionally visit the flowers to sip nectar, especially from those with easily accessible, shallow corollas. However, Clematis is not typically a primary host plant for the caterpillars of butterflies or moths.