Rhododendron vs. mountain laurel vs. azalea — What's the difference?

It’s easy to get azaleas, mountain laurels, and rhododendrons mixed up because they have so many similarities: all three are flowering shrubs that include species native to North America. Here’s the difference between these three plants and how to find their native varieties.

Azaleas, mountain laurels, and rhododendrons are all gorgeous shrubs that include dozens of species native to North America. Like other native plants, these native shrubs thrive in their home areas with just rain, minimal care, and no need for fertilizer. Any of these three shrubs are perfect for beginner gardeners, or for anyone who wants a beautiful garden without lots of work.

While these plants all belong to the same plant family (Ericaceae), each of these native species has its own set of defining characteristics that set them apart from one another. In this article, we’ll share the similarities and differences among these three beloved native plants and include ways to use all three in your landscaping.

First, let’s meet these three gorgeous native shrubs!

Azalea

(RHODODENDRON)

There are 18 species of azaleas native to North America. Azaleas cover themselves with five-petaled flowers in the spring. Each of these flowers comes with long “eyelashes” (called stamens) emerging from the center. Native azaleas lose their leaves in the winter (the word for this is deciduous). To make it a little confusing, azaleas are all included within the Rhododendron genus group.

Mountain Laurel

(kalmia)

All mountain laurel species are native to North America. Mountain laurels have tiny geometric-shaped flowers and are evergreen (keep their leaves year-round.) You’ll know you’ve got a mountain laurel if the Latin name starts with Kalmia.

Rhododendron

(Rhododendron)

There are 850+ rhododendron species worldwide with ten native to North America. Native rhododendrons are known for their dense clumps of large flowers and their large glossy evergreen leaves. Rhododendrons typically bloom in late spring or early summer, depending on the variety.

You can already start to see from the pictures and descriptions above what the differences are between the plants. Let’s dig deeper (pun intended) into their similarities and differences.

First, here’s what they have in common:

Similarities between azaleas, mountain laurels, and rhododendrons

There are three similarities between these plants:

Family ties
Flowers
Needing some shade

All three are in the same family

Rhododendrons, azaleas, and mountain laurels are all members of the Ericaceae family, commonly known as the heath family. This family includes numerous other flowering plants, such as blueberries and cranberries.

All three plants flower

One of the defining features shared by these three plants is their spectacular display of vibrant flowers, which adds beauty and color to landscapes during their respective blooming seasons.

However, each plant has different blooming seasons! More on that in a few paragraphs…scroll on to find out more.

All three like some shade

All of these shrubs are “understory shrubs,” or shrubs that live naturally underneath larger trees. To help mimic this environment, plant them in semi-shady spots. Some species—like Rosebay Rhododendrons—even flower and enjoy deep shade placements. The only spot that won’t work is full sun.

The basic shared traits between all three plants end there.

Now, let’s find the differences between these plants.

Differences between azaleas, mountain laurels, and rhododendrons

The differences between these three plants include:

Leaves (whether they are evergreen or not)
Size
Bloom time

Mountain laurels and most rhododendrons are both evergreen

After mountain laurels and native rhododendrons bloom, their evergreen glossy leaves look great year-round. Because of their evergreen ways, these two plants are perfect shrubs to plant in highly visible areas. If you live in the Northeast, Midwest, or Mid-Atlantic, plant a few of each when you can.

Rhododendrons in the winter still have their green leaves.

Mountain laurels are still green, even in the snow.

On the other hand…

Native azaleas are deciduous

North American native azaleas are deciduous, which means they lose their leaves in the winter. The good news is that many native azaleas’ leaves turn beautiful colors in the fall, giving lots of color even when their blooms are long gone.

Now, let’s talk about the difference in their size.

Mountain laurels tend to be smaller

Mountain laurels are compact, smaller shrubs that grow between 3 to 8 feet. Their branches grow in more open, sculptural forms.

Native rhododendrons and azaleas are typically larger shrubs or even small trees, reaching heights of several feet or more. They often have a more upright growth habit and can form dense clusters of foliage, unless pruned to look differently.

And one more plant to mention…

Now that you know the differences and similarities between azalea, mountain laurel, and rhododendron, we’d like to introduce one more native shrub: Texas Mountain Laurel.

Texas Mountain Laurel

(DERMATOPHYLLUM SECUNDIFLORUM)

Texas Mountain Laurel is native to Central Texas through to New Mexico. This species has flowers that smell glorious. Read about Texas Mountain Laurel.

We know what you’re thinking—another plant?! But this one is worth meeting.

Texas Mountain Laurels are known for their spectacular purple blooms that smell amazing—most gardeners describe the scent as being like Grape Kool-Aid. If you live in the Southwest—plant a few immediately. Here’s our Texas Mountain Laurel plant profile for more info.

Now that you’ve met these native beauties, let’s talk about what to consider when buying native Mountain Laurel, rhododendrons, and azaleas for your garden.

This first tip is to check the nursery tag twice, to make sure you’re buying native.

When going to the nursery: Stick to the native varieties

We mentioned earlier—a few of these plants have huge, world-spanning plant families. Rhododendrons, for instance, have 850+ plants from all over the world in their group. And sadly, most big-box nurseries only carry the non-native types.

So how do you make sure you’re buying native?

Tips for buying mountain laurel

Thankfully, buying native Mountain Laurel is easy, because:

Any mountain laurel you see—whether a true native or a cultivar—comes from plants native to North America.
Feel confident that when you see a Latin plant name that starts with Kalmia, you’ve found a native shrub.

For native azaleas and rhodos, it’s a little more complicated. You’ve got to check the tag.

Tips for buying native azaleas and rhododendrons

It’s harder to ensure it’s native when it comes to azalea and rhododendrons. It is worth repeating that there are hundreds of species within the rhododendron genus; most of which are native to Asia. When you’re looking for native azaleas or native rhododendrons:

Jot down the common and Latin plant name you’re looking for (and bookmark our native azalea and rhodo pages, which include them all!)
Look for the Latin name on the tag to be sure it’s native

No, you do not have to learn Latin

Don’t let the Latin names intimidate! Planting native does not have to feel like a botany exam. (We’ve written a whole article on how Latin naming should not scare any of us away from gardening.) If we’ve gotten used to saying words like macchiato and non-comedogenic—don’t let a few Latin botanical names stand in the way of a gorgeous yard.

When in doubt, ask the nursery sales staff. Many Master Gardeners and fellow plant nerds work at local plant nurseries. Bring your list of native plant dreams and they can help you find native azaleas or rhodos, or even special order them for you.

Now you know the basic differences between native azaleas, mountain laurel, and rhododendrons! We hope this gives you the inspiration to plant all three in your semi-shady or shady gardens. Each of these native shrubs is easy to plant, easy to care for, and saves hundreds of hours of work compared to lawn care. Because all of these shrubs are perennials, they will come back year after year. Spend a morning or afternoon planting one of these shrubs and watch them return beauty for decades.

Looking for other flowers, shrubs, and trees to plant? We’ve got you! Pick your region and find your favorites: