Ivy is typically considered an invasive garden plant but homeowners should think twice before ripping it out of their gardens. This plant is vital to pollinators including honeybees, who may lack food sources during the fall season. A study recently published in the Insect Conservation and Diversity journal notes the important role that ivy plays in the life of urban pollinators in Sussex, England.
When honeybees return from foraging they perform a dance to tell their hive mates where to find flowers rich in pollen and nectar. Researchers decoded this movement and used the resulting data to identify where the bees go and what plants they feed on during different times of year. They discovered a decrease in foraging distance from summer to autumn. Ivy blooms mainly during the months of September and October, suggesting that a nearby abundance had a beneficial effect on foraging habits of bees.
With a high-quality source of pollen and nectar available late in the flowering season, a bee colony has a higher chance of living through the winter. Researchers studied the pollen that honeybees took back to their hives to determine what proportion came from ivy. They also measured the sugar concentration of nectar collected from ivy flowers to determine how many honeybees were collecting nectar from ivy plants.
Notable discoveries included the fact that 80 percent of honeybees collected nectar rather than pollen from ivy plants. Surprisingly, the ivy nectar was considered high-quality due to its 49 percent sugar content. The resulting honey is not nearly as rich and robust as pure manuka honey but the discovery was an interesting one nonetheless. An average of 89 percent of the pollen pellets delivered to hives by the worker bees came from ivy plants.
In Sussex, a county in southeast England, ivy is commonly found in both towns and the countryside. A number of different insects including flies, late-season butterflies, and a special bee called the ivy bee pay visits to this plant. During September and October, flowering ivy is the main source for pollen and nectar in this region.
Researchers noted that ivy plays such an essential role to honeybees and other insects that if it did not exist, they might try to invent it. Fortunately, companies that specialize in New Zealand manuka honey do not need to contend with this issue. The sun always seems to be shining on the tea tree bush that yields nectar used to make the sweet substance.