Rhododendron is a large genus of woody plants in the heath family, with 11 species in Pennsylvania, both evergreen and deciduous. Known for their showy, fragrant blooms, rhododendrons produce white, pink, or purple flowers, which grow in clusters at the ends of branches and bloom later in spring. Each flower is tubular, bell, or funnel-shaped, featuring five lobes and ten stamens, adding to its distinctive appearance.

This woody, widespread shrub varies in size, ranging from small, compact forms to tree-like heights. Typically growing 4 to 10 feet tall and some species reaching up to 15 feet, it features lush, dark green, elliptic leaves. Their undersides are tan, woolly, and leathery, measuring up to 10 cm, with some exhibiting a slightly scaly texture. Seeds are somewhat ornamented at one end and released from terminal clusters of dried capsules.

Rhododendrons prefer growing in dappled shade with protection from afternoon sun, in acidic, well-drained soil, with root rot a possibility otherwise. Stem and twig fungal dieback is a major disease of the rhododendrons as is the fungus bud blast, brought to the plant by the rhododendron leafhopper, which can cause buds to turn brown and dry before they can open.

Rhododendrons are found on rocky riversides, wooded stream banks, and in high elevation forests. They are a magnet for pollinators like bees and butterflies while borers, weevils and larvae of caterpillars devour them. Deer like to browse on rhododendrons causing damage to the leaves, trampling the plants and uprooting seedlings while rabbits and squirrels also like to browse on the shrub. In spite of the its beauty, the Rhododendron is toxic to humans, cats, dogs and livestock.

The genus name rhododendron derives from the Greek word rhodo, which means rose, and dendron, which means tree.