The recent proliferation of legal Cannabis sativa cultivation, including industrial hemp, has led to a curious observation: bees are frequently seen foraging in these fields. This interaction between a recognizable pollinator and a plant historically associated with wind dispersal has generated widespread public interest. Understanding why bees visit a plant that does not seem designed to attract them requires looking closely at the specific biology of Cannabis and the foraging needs of the bee community. The answer lies not in a sticky, sweet reward but in a dusty, protein-rich resource often overlooked by other flowering plants.
The Biology of Cannabis Pollination
The Cannabis sativa plant is not a typical flowering species for insects because its reproductive strategy, known as anemophily, relies on the wind. This means the plant has not evolved common features used to attract bees, such as brightly colored petals or the production of sweet nectar. Lacking these visual and gustatory signals, the plant instead generates massive quantities of lightweight pollen designed to be carried by air currents.
The structure of the cannabis flower reflects its wind-pollinated nature. Female plants display fine, hair-like pistils to catch airborne pollen, while male plants produce small, inconspicuous flowers in clusters that rupture to release a cloud of dust-like pollen. Since Cannabis does not offer nectar, the primary reward bees seek for honey production, it offers little incentive for an insect to expend energy visiting it. This suggests that any observed bee activity must be driven by a resource other than nectar.
Why Bees Visit Cannabis Plants
Despite the plant’s lack of nectar, bees visit cannabis fields almost exclusively to collect the abundant pollen produced by male plants. This behavior is primarily observed during a phenomenon known as “pollen dearth,” which occurs in late summer and early fall when many traditional floral sources have finished blooming. Large hemp or cannabis fields can provide a crucial nutritional resource during this period of scarcity, making the plants a valuable “food of last resort.”
Bees collect this pollen for its protein content, which is essential for feeding developing larvae in the hive. Studies on industrial hemp pollen show it contains moderate levels of protein (typically 6.05% to 6.89%), along with necessary amino acids and fatty acids. Although its nutritional profile is adequate, its sheer availability during a time of floral shortage makes it highly attractive.
The high volume of pollen produced by Cannabis is a direct result of its reliance on wind-pollination, ensuring a significant amount of protein is available to foraging insects. Bee species observed visiting the plants include honey bees, bumble bees, and sweat bees. In some cases, bees may also collect resin from the plant material to use in the production of propolis, a sticky substance used to sanitize and seal the hive.
The Effect of Cannabinoids on Bees
A common concern is whether the chemical compounds in the plant, such as THC and CBD, affect the bees or contaminate the honey they produce. Cannabinoids are largely concentrated in the sticky, microscopic glands called trichomes, found most densely on the female flower buds grown for consumption. The pollen produced by male plants, which bees actively collect, contains only trace or undetectable levels of these compounds.
More significantly, research indicates that bees lack the specific cannabinoid receptors necessary for the compounds to have a psychoactive or toxic effect. Unlike mammals, insects do not possess the endocannabinoid system that THC interacts with to produce a “high.” This biological difference means the compounds are simply passed through the bee’s system without consequence.
Since Cannabis does not produce nectar, the raw material for honey, bees cannot make “cannabis honey” naturally. Honey is a water-soluble product, while cannabinoids are fat-soluble, meaning they do not dissolve or transfer into the honey. Therefore, the interaction between bees and cannabis fields appears to be purely nutritional, providing a timely protein supplement for the bee colony without chemical complication.