First off, the flowers of many rhododendron and azalea plants are chock full of nectar. When in bloom, these shrubs are like neighborhood fueling stations for bumble bees.

Why do bees like rhododendrons?

Rhododendron, bees and toxins

Rhododendron are insect pollinated and produce large amounts of sugar-rich nectar to 'reward' visiting pollinators. A number of species of bees are known to pollinate rhododendron, including honey bees. ... The most important (by amount) diterpine in rhododendron nectar is grayanotoxin.

Are rhododendrons bad for honey bees?

The ABC & XYZ of Bee Culture mentions that both the nectar and pollen of rhododendron are poisonous to bees as well as humans. Although the toxin can kill the bees, it is well diluted with water in the nectar.