Rhododendrons, azaleas... is there much of a difference? Well, yes! Let our horticulturalists take you through everything you need to know about azaleas and rhododendrons, from how they bloom to their foliage and maintenance requirements.
Difference between azalea and rhododendron
At first glance, azaleas and rhododendrons look very similar. Although these ornamental flowering shrubs were once classified separately, they're now both categorised under the genus Rhododendron.
While many gardeners use the terms interchangeably, there are notable differences between rhododendrons and azaleas, which may influence your choice of shrub. At Gardeners Dream, we carefully label all our plants to make differentiating simple, but to help you decide which would work best in your garden, here are the main differences between azaleas and rhododendrons.
Leaves
Rhododendrons have large, thick leaves with a leathery texture. Some have small spots or scales on the leaf undersides.
Azaleas have smaller pointed leaves with smooth-surfaced undersides.
Size
Azaleas are small and bushy. Most azaleas stay small and manageable, with some reaching full height at just two feet tall.
Rhododendrons are typically larger shrubs, though you can buy dwarf varieties. The largest rhododendrons can reach 20 feet. Hybrids and cultivars are often bred to limit their height; keep this in mind when choosing a shrub for your garden.
Flowers
Azaleas produce solitary blooms, with one to three azalea flowers per stem. The shrub has many slender stems and the funnel-shaped flowers have up to five stamens per flower.
Rhododendrons produce dense flower clusters called trusses on short stems. Each bell-shaped flower has ten or more stamens.Â
Both azaleas and rhododendrons bloom from late spring through to mid-summer, with most looking their best around May and June. They also produce similar coloured flowers. Purple, orange, yellow, white, red and pink are all common, though azaleas tend to have more varied shades. Azalea flowers often have a stronger fragrance.
Evergreen or deciduous
Azaleas are usually deciduous, though you may find some evergreen azaleas in warm climates. Azaleas grown indoors are often evergreen.
Rhododendrons are mostly evergreen, though you may find a few deciduous species that drop their leaves in the autumn.
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Summary of azalea vs rhododendron
| Azalea | Rhododendron | |
| Number of Stamens | Usually 5 but up to 10 | 10 or more |
| Flowers | Usually Solitary/Terminal | Almost Always in Trusses |
| Leaves - Texture | Soft and Smooth | Leathery or Scaly Underneath |
| Leaves - Size | Smaller and Thinner | Bigger and Thicker |
| Flower Shape | Tube-Funnel-Shaped | Bell-Like |
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Should you grow azaleas or rhododendrons?
Rhododendrons and azaleas have similar planting and care requirements. They both need acidic soil and partial or dappled shade. The biggest factors influencing your choice will be the space you have available and your soil type.
If you have alkaline soil, then you'll need to grow these shrubs in pots. Azaleas are ideal for containers as they're more compact plants. They're also good for smaller flower beds, as they won't overwhelm other plants. On the other hand, if you have a spacious woodland border and acidic soil, rhododendrons will give you height and structure, as well as year-round colour.
Find our more about how to grow and care for these beautiful shrubs in our rhododendron care guide and azalea care guide.
You can find both varieties, as well as many other flowering shrubs suitable for the UK climate, at Gardeners Dream. Did you know that we offer free delivery over £50 when you shop our garden shrubs?
FAQs
When do Rhododendrons bloom?
Rhododendrons bloom in the spring or summer.
When do Azaleas bloom?
Azaleas bloom in the spring, summer or autumn.
Are Azaleas evergreen?
Most Azaleas are deciduous, though evergreen Azaleas do exist and make great houseplants.
Are Rhododendrons evergreen?
Yes, most Rhododendrons are evergreen shrubs, though deciduous Rhododendrons do exist.
