Rhododendron & Azalea

Rhododendron and azaleas are adored for their spectacular spring flowers. They also have attractive foliage, sometimes year round, and are useful companion plants in the shrub border and foundation plantings.

What is the difference between Rhododendrons and Azaleas?

Both azaleas and rhododendrons are included in the genus Rhododendron. In our area, the rhododendrons are evergreen with larger, bolder foliage while the azaleas can be either evergreen or deciduous (leaves shed in fall) with smaller leaves.

Rhododendrons are either large leaf or small leaf types:

  • Large leaf types have leathery leaves 3 to 6 inches long and 1 to 2 inches wide, and bloom in mid to late May. They grow best in morning or filtered sun with protection from strong winter sun and wind.

  • Small leaf types have leaves 1 to 2 inches long and 1/2 to 1 inch wide, and bloom in late April. They grow well in full sun to part sun.

Azaleas are either evergreen or deciduous types:

  • Evergreen types may still lose a portion of their leaves going into winter. Blooming in late April, they grow best in morning or filtered sun with protection from strong winter sun and wind.

  • Deciduous types have been bred for cold hardiness and rich flower colors. Blooming in late May into June, they grow best in full sun to part shade. The leaves often show good fall color.

The hardiness temperature listed for each rhododendron and azalea is the flower-bud hardiness. Dropping below this winter temperature means the plant will probably not flower the following season.

Large Leaf Rhododendron

Name Size Description
Catawbiense Album 5’x5′ Pale lilac buds open into pure white blooms with yellow spots in the throat. Hardy to -25° F
English Roseum 5’x5′ Rosy pink flowers. Hardy to -25° F
Highland Purple Passion 6’x4′ Rich purple flowers. Vase-shaped habit. Hardy to -25° F
Hoopla 5’x5′ Rose pink flowers with yellow throat. From UConn. Hardy to -20° F.
Inkarho Lakeview Pink 5’x5′ Light pinkish violet flowers. From Germany, this type of rhododendron is a little more tolerant of alkaline soil. -25° F
March Madness 5’x5′ Frilly rosy flowers with a red blotch. From UConn. Hardy to -25° F
Nova Zembla 5’x5′ Dark red flowers. One of the best dark red rhododendrons for Midwest. Hardy to -25° F
Roseum Elegans 5’x5′ Lavender pink flowers. Deep Olive Green Foliage. Hardy to -25 F
Slam Dunk 5’x5′ Rose purple flowers with burgundy throat. From UConn. Hardy to -20F

Small Leaf Rhododendron

Name Size Description
Olga Mezitt 3’x4′ Deep pink flowers blooming after PJM. Light red fall foliage. -30° F
PJM 5’x5′ Lavender pink flowers. Mahogany fall foliage. Proven performer. -25°
PJM Landmark 5’x5′ Dark lavender pink flowers. Mahogany fall foliage. -25° F
Sugar Puff 3’x3′ White flowers edged in pink. Bold red stems in winter. Heavy bloomer. -20° F

Evergreen Azalea

Bixby 2’x3′ Bright red flowers. Small, dark green leaves. Dense, compact form. -20° F
Chalet Exclusive Introductions 4’x4′ Chalet’s very own azaleas are varieties of the hardy and vigorous Korean azalea. Available in Appleblossom, Blush, Glowing Pink, Orchid, Plum and Rose. -25° F
Compact Korean 4’x4′ Pale lavender flowers. Orange-red fall color. Sheds lower leaves in winter. -25° F
Karens 4’x4′ Lavender purple flowers. Sheds lower leaves in winter. -25° F
Rosebud 4’x4′ Pink rose-like buds open to rosy pink flowers. Orange-purple fall color. -20° F
Cannon’s Double 4’x4′ Double flowers in shades of peach, pink and cream. -20° F
Gibraltar Exbury 5’x4′ Flame orange, frilly flowers. Orange, yellow and red fall color. -20° F
Klondyke Exbury 5’x4′ Golden yellow, fragrant flowers. Bronzy, mildew resistant foliage. -20° F
Lemon Lights 4’x3′ Yellow, fragrant flowers. -35° F
Mandarin Lights 4’x4′ Orange-red flowers with ruffled petals. Bronzy purple fall color. -35° F
Northen Hi-Lights 4’x5′ Creamy white, fragrant flowers with yellow accents. Red-purple fall color. -35° F
Red Sunset Exbury 5’x4′ Deep, true red flowers with frilly petals will attract hummingbirds. -20° F
Rosy Lights 4’x5′ Dark pink, fragrant flowers with rose shading. -35° F
White Lights 5’x5′ White, fragrant flowers from pink buds. Burgundy fall foliage. -35° F