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TREES & plants

Azalea 'Northern Lights' series

Rhododendron 'Mandarin Lights' in full flower.

A hardy series of azalea hybrids (Rhododendron) developed for bud hardiness in Minnesota to withstand cold temperatures as low as -35° F without significant damage. Azaleas are deciduous, drop their leaves in fall, and have five stamens in each flower. Should be sited in protective area in a well-drained soil. Numerous colors are available.

This plant has some cultivated varieties. Go to list of cultivars.

Botanical name: 
Rhododendron
All Common Names: 
Azalea 'Northern Lights' series
Family (English): 
Heath
Family (Botanic): 
Ericaceae
Tree or Plant Type: 
  • Shrub
Native Locale: 
  • Non-native
Landscape Uses: 
  • Container, 
  • Foundation, 
  • Massing, 
  • Mixed border, 
  • Specimen
Size Range: 
  • Medium shrub (5-8 feet), 
  • Small shrub (3-5 feet), 
  • Low-growing shrub (under 3 feet)
Light Exposure: 
  • Full sun (6 hrs direct light daily), 
  • Partial sun/shade (4-6 hrs light daily)
Hardiness Zones: 
  • Zone 3, 
  • Zone 4, 
  • Zone 5 (Chicago), 
  • Zone 6, 
  • Zone 7
Soil Preference: 
  • Acid soil, 
  • Moist, well-drained soil
Season of Interest: 
  • Mid spring, 
  • Late spring, 
  • Early summer
Flower Color & Fragrance: 
  • Fragrant, 
  • Orange, 
  • Pink, 
  • Purple, 
  • Red, 
  • White, 
  • Yellow
Shape or Form: 
  • Oval, 
  • Round, 
  • Upright
Growth Rate: 
  • Moderate
More Information: 

Size and form

Rhododendron Northern Lights™ Series is a cross between Mollis hybrid azalea (R. kosteranum) and Roseshell rhododendron (R. prinophyllum).
Most are upright to rounded in habit reaching 3 to 4 feet high.

Tree & Plant Care

Azaleas have fine, shallow root systems, so well-drained soil is a must, ideally rich in organic matter.
Plants prefer acid soil (5.0-6.0 pH), if too alkaline leaves will develop chlorosis.
Can be grown in full sun in a protected site but does best in part shade.
Susceptible to black walnut toxicity, do not grow under walnut trees.
Light pruning to remove dead wood and promote bushier growth.

Disease, pests, and problems

Leaf spots, lacewings, leaf gall, root rots in wet soil

Native geographic location and habitat

Of hybrid origin.

Attracts birds, pollinators, or wildlife

Butterflies and bees

Bark color and texture 

Slender, straw-brown

Leaf or needle arrangement, size, shape, and texture

Alternate, deciduous, elliptical to lanceolate, 1 to 3 inches long, thin textured.
Medium green turning a bronzy purple fall color.

Flower arrangement, shape, and size

Flowers clusters (trusses) up to 12 appear before the leaves. Each fragrant flower is tubular, 5-petaled fused near center. Available in many colors.

Fruit, cone, nut, and seed descriptions

Sterile, no seed capsule produced.

Cultivars and their differences 

Candy Lights Azalea (Rhododendron 'Candy Lights'): lavender-purple, 3 to 4 feet high and wide.

Golden Lights Azalea (Rhododendron 'Golden Lights'): golden yellow flowers 2 inches across, 4 feet high and wide (1986 introduction).

Mandarin Lights Azalea (Rhododendron 'Mandarin Lights'): mandarin orange, 4 to 5 feet high and wide.

Northern Hi-lights Azalea (Rhododendron 'Northern Hi-lights'): creamy white flowers with bright yellow upper petal, 4 to 5 feet high and wide (1994 introduction).

Orchid Lights Azalea (Rhododendron 'Orchid Lights'): orchid-colored flowers, 3 to 4 feet high and wide (1986 introduction).

Pink Lights Azalea (Rhododendron 'Pink Lights'): light pink color, highly fragrant, 8 feet high and wide (1984 introduction).

Rosy Lights Azalea (Rhododendron 'Rosy Lights'): deep rose color, highly fragrant, 8 feet high and wide (1984 introduction).

Spicy Lights Azalea (Rhododendron 'Spicy Lights'): salmon color, slightly fragrant, 6 feet high and 8 feet wide.

White Lights Azalea (Rhododendron 'White Lights'): pink buds open to white flowers with yellow blotch, very fragrant, 5 feet high and wide.

Rhododendron or Azalea 'Northern Lights' series