Rhododendron

( roh - duh - DEN - drun )

At-A-Glance Information

Rhododendron is a genus that includes evergreen and deciduous woody shrubs and trees. Most species are native to eastern Asia and the Himalayan region, and some are native to greater Asia, North America, Europe, and Australia. These plants produce green foliage on upright stems and are valued for their large, showy clusters of springtime flowers. They thrive in the landscape when grown in partial shade and have moderate water needs. Use these shrubs as focal points in mixed beds and borders, as foundation plantings or privacy screening, in containers on patios or walkways, or as members of woodland gardens underneath Pine or Oak Trees. Take care when planting these shrubs and trees in the landscape, as all plant parts are toxic to humans and pets if ingested.
Quick Question: What's the difference between Azalea and Rhododendron?
In short, all Azaleas are Rhododendrons, but not all Rhododendrons are Azaleas. Rhododendron and Azalea were once two separate genera, and in 1834 Azalea was merged into Rhododendron. Today, Azaleas are represented as two subgenera in the Rhododendron genus: Pentanthera (deciduous Azaleas) and Tsutsusi (evergreen Azaleas). There are roughly 70 to 100 species of Azalea worldwide and more than 10,000 registered cultivars and hybrids, all of which are commonly referred to in the horticultural trade as Azaleas, though their species name begins with Rhododendron.

Rhododendron Species and Varietals

Rhododendron is the largest genus in the family Ericaceae and includes over 1,000 species. The plants in this genus are closely related to those in Kalmia (Mountain Laurel), Vaccinium (Blueberry and Cranberry), Pieris (Fetterbush), Erica (Heath) and Calluna (Heather). The ideal growing zones for Rhododendron vary depending on the species cultivated; for more information, see the descriptions below. To find your zone, click here: Zone Map.

​Rhododendron arborescens (Smooth Azalea, Sweet Azalea, Tree Azalea, Smooth Honeysuckle)
This deciduous species is native to the eastern United States, and reaches a height of between 8 and 20 feet tall when mature. These shrubs generally bloom in spring and early summertime, producing impressive white to pinkish flowers with red stamens. Leaves can become deep purple to red in cooler temperatures. Smooth Azalea grows well in USDA hardiness zones 4-7.

​Rhododendron arboreum (Rhododendron delavayi) (Tree Rhododendron, Burans, Gurans, Lali Gurans, Tree-Like Rhododendron, Shù Xíng Dù Juān, 树形杜鹃, 打马)
This evergreen shrub or small tree is native to Bhutan, China, Myanmar, Nepal, Sri Lanka, Pakistan and Thailand. It is the national flower of Nepal, and a specimen discovered in 1993 in India holds the record for the tallest Rhododendron at 65 feet. Flowers are red, pink, or white. This species is suited for USDA hardiness zones 7b-9b.

​Rhododendron argyrophyllum (银叶杜鹃, Yín Yè Dù Juān, Chinese Silver Rhododendron, Silver-Leaf Azalea, Silver-Leaf Rhododendron)
Evergreen shrub native to forested slopes in China. Leaves are green above and silvery underneath, and flowers are pale pink and bell-shaped, present on shrubs in late springtime. These plants can reach up to between 10 and 23 feet tall when mature. Cultivar 'Chinese Silver' has striking silver-white leaf undersides and deep pink flowers. This species grows well in USDA hardiness zones 7-9.

Rhododendron austrinum (Florida Flame Azalea, Honeysuckle Azalea, Southern Yellow Azalea, Orange Azalea)
This species is native to Alabama, Florida, Georgia and Mississippi in the United States. It grows well in USDA hardiness zones 6-9 and typically forms a large deciduous shrub. These plants can reach up to 8 to 12 feet tall and 6 to 10 feet wide at maturity. Flowers are brilliant yellow, gold, orange, and reddish and are highly fragrant. They bloom in early springtime before or just as leaves emerge for the season.

​Rhododendron calophytum (Beautiful-Face Rhododendron, Beautiful Rhododendron, Měi Róng Dù Juān, 美容杜鹃)
This evergreen species of large shrub is native to forested areas of central and eastern China, and reaches up to 40 feet tall and 26 feet wide at maturity. It grows well in USDA hardiness zones 6-9. Flowers are white to pale pink, spotted with maroon on their interiors. They bloom in springtime. 
Rhododendron calendulaceum (Flame Azalea, Yellow Honeysuckle)
Flame Azalea is native to the eastern United States, and is suited for growing in USDA hardiness zones 5 through 8. These shrubs can reach up to between 4 and 12 feet tall and 4 and 10 feet wide at maturity. In tree form, they can reach up to 30 feet tall. Flowers are brilliant apricot, red, yellow, orange, and scarlet hues with protruding stamens. Foliage is deciduous. This species is a parent to hybrids such as 'Ghent', 'Knap Hill', 'Maid in the Shade', 'Mollis', and 'Northern Lights'. Cultivars of this species include 'Cattooga', 'Cherokee', 'Golden Sunset', 'Golden Yellow Flame', 'Smokey Mountaineer', 'Mandarin Red' and 'Wahsega'.

Rhododendron catawbiense (Catawba Rosebay, Catawba Rhododendron, Mountain Rosebay, Purple Ivy, Purple Laurel, Purple Rhododendron, Red Laurel, Rosebay, Rosebay Laurel)
This species of Rhododendron is native to the eastern United States (Appalachian Mountains from West Virginia through northern Alabama). It is named for the Catawba River. It forms a dense, suckering shrub to 10 feet tall (rarely 16 feet). Leaves are evergreen and flowers are violet-purple with small dark spots or streaks. These shrubs are in bloom in spring and summer and are suited for USDA hardiness zones 4-8. Cultivars of this species include 'Alba' (with white flowers that open from pink buds), 'Roseum Elegans' (with soft rose-pink flowers, good in cooler climates), 'Boursault' (with lilac pink blooms to 6 feet tall), 'Purpureum Elegans' (rich blue-purple to lavender flowers) and 'Catawbiense Grandiflorum' (with large lilac flowers with tan speckles; to 6-8 feet wide).

​Rhododendron caucasicum (Caucasian Rhododendron, Georgian Snow Rose)
This evergreen species is native to the Transcaucasus and Anatolia. It is a parent species of hybrid cultivar 'Christmas Cheer' (deep pink buds and pale pink white flowers) and 'Nobleanum' (classic hybrid with rose-red flowers). The main cultivar of the species is 'Caucasicum Pictum', with frilled pink flowers that have darker pink markings. ​Caucasian Rhododendron is suited for USDA hardiness zones 5-8.

​Rhododendron falconeri (Falconer Rhododendron)
This species is native to the eastern Himalayas and forms a large evergreen shrub or tree. In its native range, it can be a dominant canopy tree in forested regions. These plants typically reach up to 40-50 feet tall at maturity, and have green leathery leaves. Flowers are white, cream, or pinkish with a prominent purple marking. Falconer Rhododendron is suited for growing in USDA hardiness zones 8 and 9.

​Rhododendron griersonianum (Vermillion Large-Flowered Azalea, Scarlet Large Rhododendron, Zhūhóng Dà Dùjuān, 朱红大杜鹃)
This rare evergreen species is native to western Yunnan, China and Myanmar, and grows in mixed forests and thickets. It can reach up to 4.5 feet tall and produces narrow green leaves and salmon-pink flowers in spring and summertime. The species is suited for growing in USDA hardiness zones 8a-9b and is a parent to many hybrid cultivars, including 'May Day', 'Tally Ho', 'Matador', 'Winsome', 'Vanessa', and 'Fabia'.

Rhododendron indicum (Satsuki Azalea, Southern Indian Azalea)
This species is native to Japan and 

Rhododendron macrophyllum (Pacific Rhododendron, California Rose Bay, California Rhododendron, Coast Rhododendron, Big Leaf Rhododendron)
This species is native to the west coast of North America, and is the state flower of Washington in the United States. It forms an evergreen shrub to between 7 and 30 feet tall at maturity, and produces large green leaves. Flowers are pink. Pacific Rhododendron is suited for growing in USDA hardiness zones 6-9 or Sunset growing zones 4-7 and 14-17.

​Rhododendron maximum (Great Laurel, Great Rhododendron, Rosebay Rhododendron, American Rhododendron, Big Rhododendron)
This species is native to a region that spans from Alabama in the United States through coastal Nova Scotia. It forms an evergreen shrub that reaches up to about 15 feet tall when mature. Flowers are white, pink, or pale purple and often have small greenish-yellow spots on them. Flowers are in bloom in summertime in the plant's native range. This species grows well in USDA hardiness zones 3-7.

​Rhododendron orbiculare (Round-Leaved Rhododendron, Tuányè Dùjuān, 团叶杜鹃)
This species is native to China, and forms a compact evergreen shrub to 10 feet tall and just as wide at maturity. They produce green, rounded leaves with a matte texture. Flowers are deep pink and bloom at branch tips in springtime. Round-Leaved Rhododendron is suited for growing in USDA hardiness zones 9-10b.

​Rhododendron pachysanthum (Thick-Flowered Rhododendron, Táiwān Shāndì Dùjuān, 台湾山地杜鹃, Nanhu Rhododendron, Nánhú Dùjuān, 南湖杜鵑)
This evergreen species produces shrubs with foliage covered in thick, fuzzy hairs that emerge rusty-brown and mature to silvery-grey. Flowers are white to soft pink and bello-shaped with tiny red spots. This species is native to Taiwan's central mountains and can reach up to 4 to 8 feet tall when mature. Thick-Flowered Rhododendron grows well in USDA hardiness zones 6-9.

Rhododendron ponticum (Common Rhododendron, Pontic Rhododendron, Wild Rhododendron, Rhododendron)
Native to southwest Europe and northwestern Asia, this species forms a dense suckering shrub or small tree to 16 feet tall (exceptionally 26 feet). Foliage is evergreen. Flowers are violet-purple and often have small greenish-yellow spots or streaks. Pontic Rhododendron is suited for growing in USDA hardiness zones 6-9. This species is considered highly invasive in the United Kingdom and Ireland.

​Rhododendron pseudochrysanthum (Yushan Rhododendron, Alishan Azalea, False Gold Flower Rhododendron, Ālǐshān Dùjuān, 阿里山杜鵑)
This species is native to Taiwan, and forms a low-growing shrub to 8 feet tall and just as wide at maturity. It is evergreen, and produces pale pink flowers in springtime that have deep pink markings on their inner surface. Yushan Rhododendron is suited for growing in USDA hardiness zones 6a-9b.

​Rhododendron rex (King Rhododendron, 大王杜鹃, False Milky-Yellow Rhododendron, Great King Rhododendron, 
Dà Wáng Dù Juān)
These evergreen trees have leathery green leaves with grey to rusty brown fuzzy undersides and reach up to 15-40 feet tall at maturity. They are native to mountain forests and thickets in southwestern China, Tibet, Myanmar and India. King Rhododendron is suited for growing in USDA hardiness zones 6b-9b.

​Rhododendron simiarum (South China Rhododendron, Monkey-Head Rhododendron, Hóu Tóu Dù Juān, 猴头杜鹃)
This evergreen species is native to southern China, and grows as either a shrub or small tree, reaching up to between 4 and 10 feet tall when mature. Bark is grey and pink flowers bloom in springtime. South China Rhododendron grows well in USDA hardiness zones 8-10.
This subgenus of Rhododendron species includes those that are native to 

​Brooks Hybrids
These Azaleas grow in zones 8, 9, and 14-24. They are hardy to 20 degrees Fahrenheit, are heat and drought tolerant, and have a compact form and large flowers that vary in color. Varietals include 'Madonna', 'My Valentine', and 'Red Wing' (pictured).

​Encore Hybrids
Zones 5-9 and 14-24. This group includes around two dozen varieties, and were bred to bloom up to three times per year starting in springtime (esp. in warmer climates). They bloom on both new and old wood. Varietals include 'Autumn Embers', 'Autumn Ruby', and 'Autumn Twist' (pictured).

​Gable Hybrids
This group grows well in zones 4-9 and 14-24. They are hardy to zero degrees Fahrenheit. In zones 4-6, these shrubs may lose leaves during the winter months. They bloom heavily in midseason. Varietals include 'Caroline Gable', 'Herbert', 'Karen', 'Louise Gable' (pictured), 'Pioneer', 'Rosebud', 'Purple Splendor', and 'Rose Greeley'.

​Girard Hybrids
This group of azaleas was bred from the Gable Hybrids, and are strong performers. Varietals include 'Girard Border Gem', 'Girard Chiara', 'Girard Rose' (pictured), 'Girard Fuchsia', 'Girard Hotshot', and 'Girard Roberta'.

​Glenn Dale Hybrids
This group of Azalea shrubs grows best in zones 4-9 and 14-24. They are hardy to zero degrees Fahrenheit, though they do drop some leaves as the weather gets colder. Some varieties in this group are tall and others are compact. Growth rate also varies. Some have small leaves and others have large leaves. Popular varieties include 'Buccaneer', 'Delaware Valley White', 'Everest', 'Glacier', and 'Pearl Bradford'.

​Gold Cup Hybrids
These Azaleas grow well in zones 14-24. They make good landscaping shrubs in areas where it doesn't get colder than 20 degrees Fahrenheit. Varietals include 'Easter Parade' (pictured), 'Sun Valley', and 'White Orchids'.
​
​Robin Hill Hybrids
These shrubs grow well in zones 4-9 and 14-24. They are hardy to 0 degrees Fahrenheit. Most are 2-4 feet tall, though some are dwarf varieties. This group includes 'Betty Ann Voss', 'Conversation Piece', 'Nancy of Robin Hill', 'Robin Hill Gillie' (pictured), and 'Hilda Niblett'.

​Satsuki Hybrids
These shrubs grow in zones 5-9 and 14-24. This group is sometimes referred to as 'Gumpo' and 'Macrantha' Azaleas. They are hardy to 5 degrees Fahrenheit. Some can be used in hanging baskets. Their large flowers come in late in the season. Well-known varieties include 'Flame Creeper', 'Gumpo', 'Gumpo Pink', 'Hi Gasa', 'Nuccio's Wild Cherry', and 'Nuccio's Wild Moon' (pictured).

Deciduous Varieties


​Fragrant Star Azalea
This variety of Azalea thrives in zones 3-9 and 14-17, and is hardy to -20 degrees Fahrenheit. This varietal has an upright growth habit and gets to be about four feet tall and a little less wide. Foliage is blue, and flowers are star-shaped and white. This is a very fragrant shrub, and is heat and mildew-resistant.

​Knap Hill-Exbury Hybrids
These shrubs grow well in zones 3-9 and 14-17 and can be upright or spreading, Blossoms are larger than those on other deciduous varieties, and color varies from whites to pinks to oranges/reds, often with contrasting blotches of color. These shrubs bloom in mid- and late-season. Some of the most popular varieties are 'Cannon's Double', 'Gibraltar', 'Homebush' (pictured), 'Klondyke', 'Arneson Gem', 'Old Gold', 'Arneson Ruby', and 'Oxydol'.

​Northern Lights Hybrids
This shrub grows in zones A2, A3, and 1-7. This is the hardiest variety of the deciduous azaleas; they can withstand temperatures down to -45 degrees Fahrenheit. These grow to be two to four feet tall and wide, with ball shaped groupings of fragrant flowers. There is no need to dead-head this variety. Popular varieties include 'Apricot Surprise' (pictured), 'Golden Lights', 'Mandarin Lights', 'Orchid Lights', 'Rosy Lights' and 'White Lights'.

​Occidentale Hybrids
This variety grows in zones 4-7 and 14-17. They are hardy to -5 degrees Fahrenheit. These can grow to eight feet tall and wide. Flowers are two to four inches wide and vary widely in color. These bloom in mid- to late-season. Examples include 'Irene Koster', and 'Washington State Centennial' (pictured).
Viscosum Hybrids
This is a popular group of hybrid azaleas with a powerful perfume and a late blooming season. Check out the following varieties:
​Rhododendron calendulaceum (Flame Azalea)
Zones A3 and 2b-6; hardy to -25 degrees Fahrenheit. Fast grower to 5 feet tall and 7 feet wide; blooms in mid-season with orange to deep red flowers. This variety is easy to grow and blooms heavily.
Rhododendron occidentale
Zones 4-7, 14-17, and 19-24. This variety can grow to be 6-10 feet tall with an upright form. Fragrant flowers appear after the plant has leafed out. Flower color varies; some are heavily marked. A trademark varietal is 'Leonard Frisbie' (pictured).
Rhododendron schlippenbachii (Royal Azalea)
Zones 3-7 and 14-17; hardy to -20 degrees Fahrenheit. This shrub is densely branched and grows to be 6-8 feet tall. Leaves are whorled at the tips of branches, and large pink, fragrant blooms appear in clusters in mid- to late-season. Great fall color. Protect from full sun.
Rhododendron vaseyi (Pinkshell Azalea)
Grows well in zones 3-7 and 14-17; hardy to -20 degrees Fahrenheit. Upright habit with a spreading, irregular form. It can grow to be 10-15 feet tall, and blooms mid-season, before leaves come in, with clusters of five to eight light pink flowers.

rhododendron species and varietals

Many people when they think about Rhododendrons envision large, leathery-leaved shrubs with clusters of showy flowers in pinks, whites, reds, and purples. These individuals may be interested to discover that Rhododendrons also include dwarf varieties that reach just a few inches tall and tree-like species that top out around 80 feet! Blossoms have a wide range of colors, can be spotted, and take a variety of different forms. The list of Rhododendron species and varieties below is divided into groups according to bloom time, and the last category is a collection of some of the most notable species of Rhododendron.
​

Early Varieties (Early Spring Bloomers)

'Northern Starburst'
Hardy to -30 degrees Fahrenheit, this variety has large flowers and thick leaves that turn dark purple in winter.
'PJM'
Hardy to -25 degrees Fahrenheit, this dense, bushy shrub reaches 4 feet tall and wide, with great purple-pink flowers and mahogany winter foliage.
'Seaview Sunset'
Hardy to -5 degrees Fahrenheit, this is a compact grower to 3 feet tall and wide, with red-orange buds that open to reveal yellow flowers with red-orange bands that mature to yellow.
'Snow Lady'
Hardy to 0 degrees Fahrenheit, this compact variety reaches 2.5 feet tall and wide, with fuzzy light green leaves and pure white flowers.

Early Midseason Varieties (Early to Mid-spring bloomers)

'Besse Howells'
Hardy to -15 degrees Fahrenheit, to 3 feet tall with large trusses of rose-red blossoms.
'Blue Diamond'
Hardy to -5 degrees Fahrenheit, with a compact, erect habit. Small lavender flowers; can take some sun in cooler climates.
'Crete'
Pink-purple buds open to light purple flowers that mature to white. Hardy to -25 degrees Fahrenheit.
'Dora Amatels'
Hardy to -15 degrees Fahrenheit, with a compact habit. Green spotted white profuse flowers with a spicy scent.
'Elizabeth'
Hardy to 14 degrees Fahrenheit and reaching three feet tall and wide. Trumpet flowers in bright red, with an early fall rebloom. Susceptible to fertilizer burn.
'Else Frye'
Hardy to 15 degrees Fahrenheit, great for an informal espalier. Whitish-pink flowers are intensely fragrant and have gold throats.
'Fragrantissimum'
Hardy to 15 degrees Fahrenheit. Bright green bristly leaves on a loose, open plant. Can be a shrub or espalier with training, and can spill over walls. White flowers are tinged pink and are very fragrant. 
'Ginny Gee'
A 2-foot tall dwarf variety with small leaves and a dense growth pattern. Bell-shaped flowers are pink and dotted with white. Profuse bloomer.
'Moonstone'
Hardy to -5 degrees Fahrenheit and reaches 3 feet tall and wide, Low, compound habit with flaring bell flowers that start pale pink and mature to creamy yellow. 
'Mrs. G. W. Leak'
(Cottage Gardens Pride')
Hardy to 0 degrees Fahrenheit; Flowers are light pink with red-purple flare.
'Patty Bee'
Hardy to -10 degrees Fahrenheit, Leaves turn dark red in cooler weather. Lemon yellow flowers.
'President Roosevelt'
Hardy to 0 degrees Fahrenheit, with dark green leaves marked with yellow. Trusses of red flowers with white centers.
'Purple Gem'
Hardy to -25 degrees Fahrenheit; to 2 feet tall and blue new foliage that matures to take on rust tones. Flowers are blue-purple.
'Ramapo'
Hardy to -20 degrees Fahrenheit, with a spreading habit. New growth is dusty green-blue and matures to dark green, flowers are pink-violet. Great in rock gardens and as a low border plant.
'Rubicon'
Reaches 4 feet tall and wide, with red flowers that have black spots.
'Sapphire'
Hardy to -5 degrees Fahrenheit, with a dense rounded habit with narrow grey-green leaves. Flowers are light blue and small.
'Taurus'
This reaches 6 feet tall and wide, and is hardy to -5 degrees Fahrenheit. Red buds open to red bell flowers with black spots. Will bloom after 4-6 years of age.
'Teddy Bear'
Hardy to 0 degrees Fahrenheit, to 3 feet tall and wide, with purple-pink flowers that age to white.

Midseason Varieties (Midspring Bloomers)

'Baden Baden'
Hardy to -15 degrees Fahrenheit to 2 feet tall and 4 feet wide, with bright red flowers.
'Bambino'
Hardy to -5 degrees Fahrenheit with peach-pink flowers blushed with yellow and dotted red. Large calyxes.
'Blue Peter'
Hardy to -10 degrees Fahrenheit, with a broad, sprawling habit and needs regular pruning. Large clusters of lavender-blue flowers wit purple markings. Can tolerate both heat and sun exposure.
'Dreamland'
Hardy to -10 degrees Fahrenheit, with a compact growth to 3-4 feet tall and large clusters of soft pink flowers edged with dark pink.
'Ebony Pearl'
Reaches 6 feet tall and hardy to -5 degrees Fahrenheit; leaves are twisted and maroon when new, maturing to copper-green. Flowers are mauve with light edges and red-brown spotting.
'English Roseum' ('Roseum Pink')
Hardy to -25 degrees Fahrenheit, with an erect habit reaching 6 feet tall, with lavender pink blooms. Hardy variety.
'Fasuosum Flore Pleno'
Hardy to -15 degrees Fahrenheit with an open, rounded habit to 6 feet tall and wide. Flowers are lavender-blue and double-form, marked with gold. Dependable, tolerates heat and sun.
'Hachmann's Polaris'
To -15 degrees Fahrenheit. Forms a three-foot mound, with hairy leaves. Flowers have deep pink edges and fade to light pink towards the center. Good in sun or shade.
'Hallelujah'
Hardy to -15 degrees Fahrenheit. Rose-red flowers and green leaves. Beautiful with or without flowers. Takes full sun.
'Henry's Red'
Hardy to -25 degrees Fahrenheit; to 5 feet tall and a little less tall. Dark red flowers.
'Holden'
Hardy to -15 degrees Fahrenheit. Reaches 4 feet tall and wide, with rose-colored flowers marked with deep red.
'Horizon Monarch'
Hardy to 5 degrees Fahrenheit, To 6 feet tall and dark green leaves. Flowers are light yellow, tinged red.
'Hotel'
Hardy to 0 degrees Fahrenheit, to three feet tall and wide, with canary yellow flowers that come to bloom at 6-8 years of age. Needs excellent drainage.
'Janet Blair'
Hardy to -15 degrees Fahrenheit, reaches 5 feet tall with a spreading habit. Large ruffled flowers are pink, cream, white and gold. Blooms midseason to late in the season.
'Lemon Dream'
Hardy to 0 degrees Fahrenheit, Dense, spreading habit, with yellow flwoers and glossy green leaves.
'Lem's Cameo'
Hardy to -5 degrees Fahrenheit, reaches 4-5 feet tall and wide. Flowers are a blend of apricot, cream and pink.
'Lem's Monarch' ('Pink Walloper')
Hardy to -5 degrees Fahrenheit, reaching 6 feet tall and wide. Large leaves and pink flowers that are darker at the edges.
Loderi Hybrids
This group has very fragrant flowers in shades of pink and white. Grows to 6 feet tall and wide. Popular varieties are 'King George' (with pink flowers that fade to white), 'Pink Diamond' (with blush flowers), and 'Venus' (with deep pink flowers).
'Loder's White'
Hardy to 0 degrees Fahrenheit, to 5 feet tall. White flowers with yellow throats and pink edges. Blooms turn pure white at maturity. 
'Mi Amor'
Hardy to 15 degrees Fahrenheit, great for mild-winter climates. Lanky habit, 
'Nancy Evans'
Hardy to 5 degrees Fahrenheit, reaching 3 feet tall with bronze new leaves. Buds are orange, and open to yellow flowers with large calyxes.
'Nova Zembla'
Hardy to -25 degrees Fahrenheit, with profuse red flowers and can take some heat.
'Noyo Chief'
Hardy to 10 degrees Fahrenheit and reaches 5 feet tall with glossy green leaves that are heavily ribbed. Bright red flowers.
'Paprika Spiced'
Hardy to 0 degrees Fahrenheit. Reaches 3 feet tall and flowers have a blend of yellow pink and orange and are dotted red with large yellow calyxes.
'Percy Wiseman'
Hardy to -10 degrees Fahrenheit, this variety has peach-yellow blooms that mature to white; a heat-resistant choice.
'Polarnacht'
Hardy to -10 degrees Fahrenheit. This shrub reaches just 3 feet tall and 6 feet wide, with flat green leaves and purple-red flowers.
'Pomegranate Splash'
A compact variety to 3 feet tall and 2.5 feet wide, hardy to 10 degrees Fahrenheit. Flowers are white with brown blotches and purple-red exteriors.
'Purple Passion'
Reaches 6 feet tall and 5 feet wide, with dark green leaves and purple flowers. Hardy to -25 degrees Fahrenheit.
'Rocket'
Hardy to -15 degrees Fahrenheit; reaches 5 feet tall and 4 feet wide, with glossy green leaves and frilly pink flowers with red blotches.
'Sappho'
This variety reaches 6 feet tall and about as wide, with white flowers that have purple spots. Easy to grow but can get gangly without pruning.
'Scarlet Wonder'
Hardy to -15 degrees Fahrenheit. This variety is a great dwarf, with shiny, quilted leaves and scarlet flowers. To 2 feet tall.
'Scintillation'
Hardy to -15 degrees Fahrenheit, with dark green leaves and pastel pink flowers with darker pink throats. Flowers age to brown-pink.
'September Song'
Hardy to 0 degrees Fahrenheit; reaches 4 feet tall and a little wider, with salmon-colored flowers that fade to gold-orange in the throat.
'Skookum'
Hardy to -20 degrees Fahrenheit, with globe-shaped red flowers. Handsome plant.
'Susan'
Hardy to -5 degrees Fahrenheit, and reaching 6 feet tall. Handsome foliage and violet-blue flowers that bloom in large clusters.
'The Honorable Jean Marie de Montague'
To -5 degrees Fahrenheit. This variety reaches 5 feet tall and about as wide, with bright scarlet-red flowers.
'Trude Webster'
This variety is hardy to -10 degrees Fahrenheit, with pure pink flowers in large clusters. Reaches 5 feet tall and as wide, a strong grower with large leaves.

Late Midseason Varieties (Mid- to Late-Spring Bloomers)

'Anah Kruschke'
Hardy to -15 degrees Fahrenheit, with lavender-blue to reddish-purple flowers and handsome foliage. Sensitive to root rot in warm, wet soil.
'Anna Rose Whitney'
Reaches 6 feet tall and wide, with great foliage. Large clusters of deep pink flowers. Hardy to -5 degrees Fahrenheit.
'Capistrano'
Hardy to -15 degrees Fahrenheit, to 3 feet tall and 6 feet wide. Bell-shaped yellow blooms.
'Catawbiense Album'
Hardy to -20 degrees Fahrenheit, with pink buds that open to white flowers with a green blotch. Reaches 6 feet tall and wide. Can take both cold and heat.
'Catawbiense Boursault'
Hardy to -20 degrees Fahrenheit, with pink-lavender flowers on a 6 feet tall and wide shrub. Can take cold and heat.
'Chionoides'
Reaches 4 feet tall and wide, with a dense, compact, rounded habit and white flowers with light yellow spots. Can take sun. Hardy to -15 degrees Fahrenheit.
'Cunningham's Blush'
Hardy to -15 degrees Fahrenheit; reaches 4 feet tall and wide, with blush pink flowers that have white blotches.
'Cunningham's White'
Hardy to -15 degrees Fahrenheit. This variety has white flowers with a green-yellow blotch.
'Daphnoides'
Reaches 3 feet tall and about as wide, with lavender-blue flowers that bloom profusely. Dense foliage; glossy deep green leaves are convex. Hardy to -10 degrees Fahrenheit.
'Elvira'
Reaches 2 feet tall and wide, with glossy green leaves that have a red tinge to them. Flowers are red. Hardy to -25 degrees Fahrenheit.
'Fantastica'
Hardy to -5 degrees Fahrenheit. Reaches 3 feet tall and wide, with long, elliptical leaves that are wooly underneath. Flowers are rose-pink with a white throat and green spots.
'Gomer Waterer'
Hardy to -15 degrees Fahrenheit. White flowers with yellow-green blotches open from pink buds. Can tolerate sun.
'Helsinki University'
Reaches 6 feet with an upright habit; hardy to -25 degrees Fahrenheit. Leaves have a red tinge when new. Flowers are purple pink and have wavy edges.
'Purple Splendour'
Hardy to -5 degrees Fahrenheit. Reaches 5 feet tall and wide, with ruffled purple flowers with black spots. Can tolerate sun.
'Roseum Elegans'
Hardy to -25 degrees Fahrenheit. 6 feet tall and wide, with olive green foliage. Flowers are lilac. This variety tolerates heat and cold.
'Vulcan'
Reaches 5 feet tall and about as wide, with brick-red flowers. Hardy to -15 degrees Fahrenheit.

Late Varieties (Late Spring Bloomers)

'Haaga'
Hardy to -20 degrees Fahrenheit and reaching 5 feet tall and wide. Upright habit, with glossy green leaves and Fuchsia-pink flowers.
'Hellikki'
This variety has narrow leaves and purple wavy flowers. Hardy to -25 degrees Fahrenheit.

Rhododendron Species

Rhododendron augustinii
This species is hardy to -5 degrees Fahrenheit and is native to western China and Tibet. Has an open growth to 6 feet tall and wide. Flowers are bell-shaped and range in color (white to lavender pink to blue). Blue-flowered varietals include 'Barto Blue', 'Electra', 'Lackamas Blue' and 'Towercourt'.
Rhododendron calostrotum keleticum
This variety, native to Myanmar, China, and Tibet, is compact (1 foot tall and 3 feet wide) with tiny dark green leaves with scaly brown undersides. Flowers are crimson-purple; blooms pop in late midseason. Hardy to -15 degrees Fahrenheit.
Rhododendron campylogynum Myrtilloides Group
Hardy to -10 degrees Fahrenheit and native to China, India and Myanmar mountains. Reaches 1 foot tall with dark green leaves. Bell-shaped plum flowers bloom in midseason.
Rhododendron degronianum yakushimanum
(Rhododendron yakushimanum)
Native to Japan, this shrub is hardy to -25 degrees Fahrenheit and forms a mound 1-4 feet tall. New growth has white hairs; flowers are pink and age to white. Varieties include 'Ken Janeck', 'Yaku Angel', 'Mardi Gras'. 'Yaku Sunrise', and 'Yaku Princess'.
Rhododendron falconeri
Hardy to 10 degrees Fahrenheit and native to the Himalayas, this species is grown as a tree, and has leathery green leaves and clusters of white-pale yellow flowers. Early-midseason bloomer, only starts blooming at an age of 10-15 years.
Rhododendron forrestii forrestii
Repens Group
Hardy to 5 degrees Fahrenheit, prostrate species native to China and Myanmar. Small clusters of bright red tube-shaped flowers in early-midseason. Great in rock gardens; require great drainage.
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Rhododendron impeditum
Hardy to -15 degrees Fahrenheit and native to China. Twiggy and dense, dwarf form with light grey-green foliage. Flowers are bluish-purple and bloom in early midseason. Use as groundcover (plant 15 inches apart). Full sun in cooler areas; needs great drainage.
Rhododendron keiskei
Native to Japan and hardy to -5 degrees Fahrenheit. Compact to 2 feet tall with bright yellow blooms in early midseason. Variety 'Yaku Fairy' is a creeping form that reaches 6 inches tall.
Rhododendron macrophyllum
(Coast Rhododendron;
Western Rhododendron)
Native to Northern California and British Columbia, hardy to -5 degrees Fahrenheit. Reaches 4-20 feet tall with leathery dark green leaves and pink-purple or white flowers spotted with red-brown. Late midseason bloom.
Rhododendron moupinense
Hardy to 0 degrees Fahrenheit and native to China, reaches 1.5 feet tall and has a spreading habit; Deep red new foliage matures to green. White or pink flowers with red spots bloom very early in the season.
Rhododendron mucronulatum
Native to China, Mongolia, Korea and Japan, this deciduous shrub has an open habit and very early bloom. Flowers are bright purple; hardy to -15 degrees Fahrenheit. Variety 'Cornell Pink' has pink flowers.
Rhododendron pachysanthum
Hardy to -5 degrees Fahrenheit; native to Taiwan. Reaches 30 inches tall; leaves have silver-brown hairs above, tan hairs underneath. Flowers are white to pale pink spotted with green or crimson. Early midseason bloom.
Rhododendron pemakoense
Hardy to 0 degrees Fahrenheit; native to the Himalayas and China. 1.5 feet tall, with small leaves and pink-purple flowers. Blooms in early season, useful in rock gardens.
Rhododendron racemosum
Hardy to -5 degrees Fahrenheit and native to China. Tend to be compact varieties, though one selection reaches 7 feet tall. Small pink flowers bloom early to midseason; easy to grow and tolerant of sun.
Rhododendron rex
Hardy to 0 degrees Fahrenheit, with upright growth to 6 feet tall. Native to China. Huge leaves with grey-brown hairs underneath. Flowers are white spotted with red, and bloom in early midseason.
Rhododendron tsariense
Native to Tibet and India, hardy to 0 degrees Fahrenheit. Compact grower to 2 feet tall; flowers are white flushed pink. Brown hairs on leaf undersides and early to early midseason bloom.
Rhododendron williamsianum
Native to Szechuan, China. Compact to 3 feet tall and a little wider. Bronze new foliage matures to green with blue-green undersides. Flowers are pink and bell-shaped, bloom in midseason.

Caring for and Pruning Azalea & Rhododendron shrubs

As with any other plant, the first step in providing good care for your azalea shrub is to choose the right spot! If you have chosen an evergreen variety, they do better in partial shade, while deciduous varieties flower more vibrantly in full sun. The best time to plant azaleas is in late spring or early fall. Soil should be well-drained and humus-rich, as well as slightly acidic (pH 4.5-6). Mulch the area under the shrub well, as this will assure that the plant gets enough water and will not dry out. Fertilizer isn't usually needed unless the soil is deprived of nutrients to begin with. Usually, the nutrients that seep into the soil from the mulch around the bottom of the plant are enough. After the plant is established, watering is only needed during dry times.

Pruning azalea bushes should be done in the spring or early summer, after they bloom. You'll know it's the perfect time for some pruning when the spent flowers begin to discolor and shrivel up. Cutting them back in late summer, fall or winter will remove flower buds and prevent the shrub from blooming in the next season. Azaleas are not well-suited for formal shapes; they are best left to grow in their natural habit. When pruning, use pruning shears to cut individual branches at the proper spot. If you are shaping to maintain the size of your azalea, pick put the branches that are outside its natural shape, that are making it look un-pruned. Then, cut each of those branches back by a third or less. Azaleas will sprout new branches from below wherever you make a cut; don't worry about cutting back to a connecting branch. If your shrub is looking a little worse for wear, you can rejuvenate it through pruning. Locate three to five of the largest branches. Then, cut these branches back by a third to a half. Trim all other branches back as though you were shaping the plant; back to about a third or less of each branch.

Propagation

To propagate an evergreen Azalea bush via cutting, follow these steps in midsummer to early autumn. Your new azalea plant will be ready to go in about a year. You will need: Pruners, Rooting Hormone (liquid or powdered), Well-Drained Rooting Medium (it should include peat moss, perlite, vermiculite, or sand), Growing Container (with a drainage hole). AND MORE?
  1. Cut several 2-5 inch stems from the new growth on a healthy azalea plant. Make your cut just above a node, or a small protrusion on the stem where a new leaf or stem will emerge. The third video in the video section below can give you a better idea of where this is exactly.
  2. Pinch off all but the top set of leaves from the cuttings; carefully to avoid damaging the stem. If the top leaves are very large and make the cutting droop over or if they are interfering with other cuttings in your growing area, cut them in half horizontally.
  3. Using your fingernail, gently scrape off the outside of the stem of your cuttings at the very bottom 1/2 inch. Then, dip the bottom of the stems in a liquid or powdered rooting hormone.
  4. Using a pencil, make a hole in the soil - or rooting medium - in the middle of the pot you will be growing the azalea in. Then, plant the stem. Place the pot in a clear plastic bag and seal it with a rubber band.
  5. Place the bag in a bright area, but avoid direct exposure to sunlight, especially in the afternoon. Cuttings will generally require no water when covered securely in plastic. If the rooting medium looks dry, spray the inside of the plastic bag with water. Do not water the soil directly.
  6. Check the cuttings after four to eight weeks for roots! To do this, remove one or two stems from your rooting medium carefully. You can use your finger or a butterknife. Work slowly to avoid damaging the new roots. Inspect the roots, and then immediately replant the stems. If the roots are 1/2 to 1 inch long, they are ready to be transplanted. Open the top of the bag up and leave it like that for about two days to allow the new plants to acclimate to the cooler air.
  7. After the cuttings have acclimated, transplant each rooted cutting to an individual pot (if it wasn't in an individual pot to begin with) filled with commercial potting soil. There is no more need for the plastic bag. Move your pot into an indoor area with bright light, but again not direct sunlight, especially in the afternoon. Keep the soil slightly moist, and allow the plant(s) to mature indoors or in a greenhouse for one year before moving them to their permanent outdoor home.

Note: Evergreen azaleas are much easier to propagate than deciduous varieties. Even if they manage to get rooted, they often fail to develop into fully grown specimens. If you'd like to attempt to propagate a deciduous azalea shrub via a cutting, the process is the same, with a few notable exceptions. Cuttings should be taken earlier in the year, usually in late spring, when the stems are soft and flexible. Rooting hormone isn't a necessity for growing evergreen cuttings, but it is critical in growing a deciduous cutting. Water the plant two days before taking the cutting, and take your cutting in the early morning when the stems are plump and well-hydrated. Otherwise, follow the directions above. Good luck!

problems and pests

Azaleas are seldom bothered by insects and diseases. For information on commonly encountered pests and diseases in the home garden, including how to deal with them, consult the following pages:
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Gallery

Azaleas and Rhododendrons can be grown in containers to add interest to your porch. 
Azaleas and Rhododendrons make a great, colorful border hedge. 
Azaleas and Rhododendrons are great at creating a 'mounding' look in your garden. 

The low-down on pruning Azaleas and Rhododendrons.
Learn how to propagate Azaleas and Rhododendrons from cuttings.

Resources

The New Sunset Western Garden Book: The Ultimate Gardening Guide (2012) - Pages 561-563, Azaleas; Pages 556 - 561, Rhododendron
Azaleas: Meet the Royal Family