Spring color bursts with 'crown jewel' pollinator

COLUMBIA, Mo. – The National Garden Bureau has selected azalea as its 2026 shrub of the year. Renowned for their colorful seasonal displays, azaleas are becoming the crown jewel in landscapes nearly everywhere, said University of Missouri Extension horticulturist David Trinklein.

There is no more iconic springtime flowering shrub than azalea, Trinklein said. Advances in hybridization have yielded new cultivars that are rebloom, are heat- and cold-tolerant and have compact growth habits, which makes them ideal for small spaces.

Azalea belongs to the genus Rhododendron,but it should not be confused with the larger shrub with evergreen, leathery leaves and bell-shaped flowers commonly called rhododendron. In short, all azaleas are rhododendrons, but not all rhododendrons are azaleas, said Trinklein.

There are two main types (sub-genera) of azaleas. The Tsutsusi group is evergreen and retain its leaves year-round. Popular members of this group include the Kurume, Girard and Gable hybrids.

In contrast, the Pentanthera group is deciduous. However, they often display brilliant foliage as temperatures fall before shedding their leaves in the autumn. Popular members of this group include the Exbury, Northern Lights, Mollis hybrids and Ghent hybrids.

Plant azaleas in early spring or fall when temperatures are mild. This gives roots time to establish before summer heat or winter chill set in. When planting, set them slightly high in the hole for good drainage. A 2- to 3-inch layer of mulch over the root zone can help newly planted azaleas retain moisture and defend their shallow root systems against temperature extremes.

Most azaleas thrive in partial shade, though some sun-tolerant varieties like Encore series and Candy Lights can handle four to six hours of sun with afternoon shade. Many North American native azaleas are understory shrubs, so they benefit from afternoon shade or filtered sunlight, particularly when grown in hotter regions.

Azaleas require an acidic (pH 4.5 to 6.0), well-drained soil high in organic matter. Adding a layer of organic mulch around azaleas can help with weed control, moisture retention and root protection during the winter.

Fertilize azaleas right after their spring bloom ends with a well-balanced, slow-release fertilizer formulated for acid-loving plants. For most traditional once-blooming azaleas, this single spring feeding is all that is needed.

Reblooming types, like Encore, may benefit from a second feeding in mid-to-late summer when grown in areas that see frequent rainfall and a long growing season. However, avoid fertilizing after Aug. 1 to discourage tender new growth going into winter. Always follow fertilizer label instructions, water thoroughly after application, and avoid over-fertilizing, which can harm the plant.

Before a hard freeze in late fall, water azaleas deeply. This helps evergreen azaleas avoid leaf browning, which happens when plants can’t absorb enough water from the soil during freezes. Maintain a 2- to 3-inch layer of mulch over the root zone to insulate shallow roots. If heavy snowfall or ice is in the forecast, drape plants in a breathable material like burlap to protect them from damage.

Azaleas are a great way to attract pollinators, Trinklein said. Bright pink and red azaleas are hummingbird magnets, while white blooms attract fluttering moths and could even be used in a moon garden. Additionally, early blooming azalea varieties give bees that have overwintered a vital first food source, helping kick-start pollinator activity in the garden each spring.

Photo

Azalea blossom. The nectar and leaves of azaleas contain toxins, so the plant should be kept out of reach of children and pets. Photo by Jud McCranie, shared under CC BY-SA 3.0, via Wikimedia Commons.