Can an Azalea Bush Grow in a Cold Climate?

Azaleas

• Azaleas are deciduous, semi-evergreen or evergreen rhododendron plants. Deciduous azaleas are native in certain areas of the United States, Canada, Japan, China and Europe. Evergreen azaleas are native to parts of Asia. Thousands of azalea hybrids are commercially available. Heat-tolerant azaleas are particularly popular garden plants in warm areas of the U.S. and Japan. The University of Minnesota has developed a series of azaleas for successful growing and flowering in the cold Minnesota winters.

Successful Cultivation

• Thoughtful site selection and careful soil preparation increase cold-climate success. Azaleas in cold climates prefer full sun or light shade. Extreme summer heat, even in cold-winter climates, is detrimental to azaleas. Avoid exposed areas of reflected heat such as south sides of buildings. Shallow-rooted azaleas dry out rapidly. Provide consistent irrigation and excellent drainage. An acid soil with a pH level of 4.0 to 5.5 is optimum. Improve the soil texture and pH level with a generous addition of organic matter. Apply an acid fertilizer once or twice during the growing season.

Northern Lights Azaleas

• The University of Minnesota Landscape Arboretum developed the Northern Lights series of azaleas as the result of an original cross between Rhodendron x kosteranum and Rhododendron prinophyllum. Plants in the Northern Lights series are released only if the flower bud is hardy to a minimum of -30 degrees F, with some tolerant to as low as - 45 degrees F. The plants grow to a mature height and width of up to 8 feet, producing an abundance of sweetly-fragrant flowers in late May. Selections in the series include the word "Lights" in the cultivar name. The series first became commercially available in 1978.

Cold-Tolerant Azaleas

• Pink Lights has light pink, sweetly scented flowers on a plant as high and wide as 8 feet at maturity. Rosy Lights is particularly showy with deep rosy-pink flowers on a plant 8 feet high and wide. White Lights grows to 5 feet high, displaying pale-pink buds opening to white flowers with a yellow blotch. Spicy Lights produces salmon-colored flowers on a plant 6 feet high with a wider spread. Golden Lights grows 4 feet high and wide with large golden flowers and improved mildew resistance. Orchid Lights is a compact plant growing to 3 feet high and wide with orchid-colored flowers. Roseshell azalea is a species native from Main to Virginia, with white to rosy-pink flowers are displayed on a compact plant. Pinkshell species azalea produces delicate, pale-pink flowers before the foliage emerges.