When it comes to azaleas, horticulturalists are spoilt for choice. Azaleas are members of the rhododendron genus, which contains over 1,000 deciduous and evergreen plants. This article will explore some of the best azalea varieties.
What are Azaleas?
Azaleas are small to medium woody flowering shrubs that belong to the large
Rhododendron genus. Azaleas come in both evergreen and deciduous varieties and are prized for their colourful spring blooms. Azaleas were originally indigenous to the forested slopes of Asia, but have since been introduced to Europe and North America.
Top Five Azalea Species
As part of the
Rhododendron genus – which contains approximately 1,024 individual plants – there are plenty of beautiful azaleas. Here are five of the best azalea varieties.
Rhododendron luteum “Yellow azalea”
Rhododendron luteum is a hardy deciduous azalea variety that is indigenous to regions of southeastern Europe and Turkey. These azaleas have vibrant yellow star-shaped flowers. These typically emerge in May and June and give off a pleasant perfume. The yellow azalea shrub can grow up to 4 metres tall and 4 metres wide.
Rhododendron “Fireball”
The Azalea “Fireball” is a deciduous species with trumpet-like orange blooms. When in bloom during May and June, the flowers produce a delicate scent. The deciduous foliage emerges as brownish-red before turning green and then orange throughout the summer and autumn. This shrub stays at a manageable size, rarely exceeding 1.5 metres tall and 1.5 metres wide.
Rhododendron “Rosebud”
This azalea is an evergreen dwarf variety that grows to 1 metre tall and 1 metre wide. Azalea “Rosebud” is named for its clusters of pink double flowers that are visible in May through June. The foliage is a medium shade of green and doesn’t fall off during the winter. Azalea “Rosebud” takes five to ten years to grow to its full size.
Rhododendron “Sea of Stars”
Rhododendron “Sea of Stars” is a dramatic deciduous shrub that flowers in June and July. The trumpet-shaped flowers emerge pink before turning white as they open. This variety produces a lovely honeysuckle-like scent. After ten years, this variety can reach up to 1.5 metres in height and width.
Rhododendron simsii
This evergreen azalea variety is frequently grown for indoor cultivation. It is also a seasonal plant often sold at Christmas time due to its red and white blooms. Specimens sold in this way are usually “forced on” to be ready for the winter season.
As potted plants,
rhododendron simsii typically grow to around 45 to 60 cm. However, they can also be grown outside in pots in warmer conditions. In the wild, these specimens grow to two feet tall.
Botanical Facts About Azaleas
Until approximately 2005, botanists had considered azaleas to be a separate species from rhododendrons. However, further studies indicated that due to a long list of similarities, azaleas should be reclassified as rhododendrons.
Now, azaleas are mixed into several subgenera of the rhododendron genus. The two main ones are the
Petanthera group, which mainly covers the deciduous azaleas and the
Tsutsuji group which represents the evergreen azaleas.
Azaleas can be differentiated from other rhododendrons by certain physical characteristics. On the whole, azaleas are smaller when mature than other rhododendrons. Azalea flowers have five stamens, while true rhododendrons have ten. Azalea flowers emerge in clusters at the tips of their more numerous stems.
Leaf structure is also different. Rhododendron leaves have a texture similar to leather, while azalea foliage is thinner and more delicate. Azaleas also often have fine hairs that cover the underside of their leaves.
Like rhododendrons, azaleas are extremely toxic to birds, cats, dogs, and humans.
Care Tips for Azaleas
Despite being prized by horticulturalists for their beautiful blooms, many azalea varieties are fairly easy to cultivate. Here’s a brief overview of the basic care tips for azaleas.
Azaleas are used to growing in slightly shaded areas with dappled, indirect sunlight under forest canopies. Avoid exposing them to direct afternoon sunlight, although a few hours of light in the morning is advantageous.
These woody shrubs grow best in slightly moist soil, so never let them completely dry out. Mulching helps retain moisture in the soil as well as providing nutrients for the plant. Azaleas need acidic soil conditions, so use ericaceous compost and acidic mulch sources such as bark or needles from conifers and pines. Keeping the soil in a pH range between 4.5 and 6.0 is perfect.
If the soil is sufficiently prepared with some acidic organic matter as mentioned above, azaleas will not need regular fertilising. Deadhead spent azalea flowers during the spring and summer. Once the flowering season has ceased, trim older or dying stems from the plant. Never cut them right back
Azaleas as Home Decor
As spectacular as they can be in the garden, azaleas also make excellent interior décor for the home. This can be either as houseplants or cut flowers. A few species of azalea, like
rhododendron simsii, are specifically grown for indoor cultivation.
Azaleas can be particularly good cut flowers because they can survive for days. Replace the water in the container every day to keep them fresher for longer. Use rainwater wherever possible when watering any type of azalea – tap water is far too alkaline.
Indoor azalea varieties prefer humid but cool locations in the home. They also need plenty of indirect sunlight. Keep the soil moist and increase acidity by using ericaceous potting mixes or watered-down solutions of black tea or coffee grounds. Different cultures have different meanings for azaleas, there are
many different events for azaleas around the world.
After their first flowering, these specimens may be able to produce a second round of flowers the following year with the right care. Once the plant has flowered, place it in a cooler room for the autumn.
During the following spring, repot the azalea and then feed it some half-strength ericaceous fertiliser every week. Move the plant somewhere with bright indirect sunlight and a temperature of approximately 16ºC to 18ºC (60 to 64ºF).
