Evergreen Azaleas Grow Guide: How to Grow Evergreen Azaleas

Evergreen azaleas (Rhododendrons) are flowering evergreen shrubs that belong to the Ericaceae plant family. They are neither perennial nor annual plants because they keep their leaves year-round. These shade-loving plants bloom star-shaped red, purple, pink, and white flowers. The flowers bloom nestled between the bush’s broad leaves, but they need sunlight to bloom.

Many evergreen azalea species are native to Korea, Japan, and China. They do not grow natively in the United States (though quite a few hybrid cultivars are now imported to the US). Evergreen azaleas can attract pollinators and form privacy screens around your property or ornamental ground cover.

All parts of the azalea are toxic to animals and humans if ingested.

Here are some of the most popular types of evergreen azaleas:

1. 1. ‘Encore’ azaleas: This hybrid of Kurume and Southern Indica varieties, creating a reblooming cultivar that grows up to three feet tall and four feet wide, blooming red, pink, or white flowers.
2. 2. ‘Girard’ azaleas: This cold-hardy cultivar blooms with flowers that come in white, scarlet, and orange hues.
3. 3. ‘Hino-crimson’ azaleas: Hino-crimson is another Kurume hybrid cultivar. This evergreen azalea bush sprouts tiny green leaves with crimson red flowers in the early spring. These flowers attract pollinators such as hummingbirds and butterflies.
4. 4. Kyushu azaleas (Rhododendron kiusianum): This evergreen to semi-evergreen shrub grows less than two feet high and sprouts lilac flowers. Plant breeders often use this particular species to create hybrid cultivars.
5. 5. Snow azaleas (Rhododendron mucronatum): Snow azaleas have upward-facing white flowers resembling snow puffs. This shrub has a long bloom season and glossy foliage. They make excellent pollination stations for bees and are somewhat fungi-resistant.
6. 6. Southern Indian azaleas (Rhododendron Indicum): These semi-evergreen shrubs sprout showy red flowers in the mid-to-late spring and early summer. Indica varieties grow to a height and spread of three feet and enjoy low light, making them suitable indoor houseplants.
7. 7. Wild thyme azalea (Rhododendron serpyllifolium): This semi-evergreen shrub sprouts magenta and light to deep pink flowers. This variety grows up to four feet with a four-foot spread.

There are many differences between deciduous and evergreen azaleas:

• Flowers: Evergreen azalea shrubs often bloom with star-shaped or round petals and shorter stamens, while deciduous azaleas bloom more tubular flowers with longer stamens.
• Growing conditions: Evergreen azaleas prefer to stay out of the direct sun and need additional protection from other extreme elements like the wind. Deciduous azaleas tolerate full sun and are more cold-hardy. Azaleas, in general, thrive best in USDA Hardiness Zones 4–9, though evergreen azaleas will do better in warmer climates.
• Growth habit: Deciduous azaleas often grow taller than evergreen species. While deciduous azaleas grow between eight and fifteen feet in height, evergreen azaleas rarely grow over six feet.
• Leaves: Deciduous azalea leaves are four inches longer than evergreen azalea leaves. Evergreen azalea leaves rarely reach lengths over two inches.
• Subgenera: Deciduous azaleas are part of the Pentanthera subgenus, while evergreen azaleas are part of the Tsutsuji genera.

Azaleas can be finicky but will survive for years in the right environment. Many common azalea cultivars are hybrids that are tricky to grow from seed, but they propagate quickly. Here is an overview of how to grow evergreen azaleas from cuttings.

1. 1. Prepare your planting spot. Evergreen azaleas require partial shade and acidic soil. Enrich the soil in your chosen grow space with potting mix, peat moss, and organic matter compost, or use a fertilizer that adjusts the soil pH level to their preference. Make sure the area does not receive full sun. Alternatively, keep your azaleas in a container.
2. 2. Obtain the cutting. Water the parent azalea plant the day before you take a branch cutting. Select healthy branches with thriving blooms and foliage from the parent plants. Use a clean pair of garden scissors to snip a four-inch branch off the plant.
3. 3. Root the cutting. Remove all leaves from the bottom inch of the cutting. Shave away some of the bark at the bottom of the cutting. Dip the cut end into rooting hormone powder and tap out the excess. Place the bottom third of the cutting into the soil medium, cover it loosely with a plastic bag, then place it in indirect sunlight.
4. 4. Water regularly. Water your cutting regularly for the next four to six weeks, taking care not to let the soil dry out too much between waterings. Gently tug on your cutting after a few weeks to check for any resistance: If there is, your cutting has started rooting.
5. 5. Transplant into the garden. Move your burgeoning azalea bush to the garden in late summer or early autumn, which will give the shrub’s shallow root systems time to establish before the winter. Dig a hole just as deep but twice as wide as the developing root ball of your shrub. Next, place the roots in the hole and backfill it with soil. Water the area deeply until the soil settles.

Follow these care tips for evergreen azaleas to keep your shrubs thriving.

1. 1. Monitor soil drainage. Make sure your container has good drainage. Occasionally, refresh the topsoil with a two-inch pine needle or wood chip mulch layer. Poor drainage and overwatering lead to root rot, which will kill your evergreen azalea bushes.
2. 2. Prune after blooming. Maintain the shape of your azalea shrub with occasional pruning if you like. Prune the bushes in the late spring after the bloom time is over (but before the following year’s flower buds set—around late summer to early fall).
3. 3. Watch for pests and diseases. Evergreen azaleas are susceptible to whiteflies, lace bugs, and spider mites. Treat these infestations with an organic insecticide or horticultural oil. Keep an eye out for fungal diseases like Ovulinia azaleae or petal blight, like mold growing on your flower petals or leaves. Cut away dead material and replace existing mulch to help treat these problems.

Grow your own garden with Ron Finley, the self-described "Gangster Gardener." Get the MasterClass Annual Membership and learn how to cultivate fresh herbs and vegetables, keep your house plants alive, and use compost to make your community—and the world—a better place.