Azalea Bonsai Tree

Written by Sandy Porter
Updated: December 30, 2022
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One of the most beautiful and most commonly found bonsai species in the world is the azalea, a flowering shrub in the rhododendron genus. The shrub naturally blooms with ease, as long as it’s planted in the right environment, and generally tends to be an easy plant to care for. The skill comes in with shaping the azalea into a small bonsai.

The plant is known for its incredible colorful blooms that may be vivid shades of reds, purples, whites, oranges, yellows, and bi-color combinations and often is the “image” folks think of when they image flowering bonsai trees.

Let’s explore the possibilities of this incredible shrub that makes for gorgeous and intriguing bonsai.

What Makes Azaleas Good for Bonsai?

Various shapes of azalea bonsai isolated on white background

Azaleas are shaped differently and styled in many ways.

©Bernd Schmidt/Shutterstock.com

Nearly every variety and species of azalea may be used as a bonsai, but the most popular hybrids are the easiest to train, grow, and care for. Ultimately, each species is generally easy to care for, though the right conditions must be met in temperatures, humidity, and soil. This makes them easy to care for plants. They’re also incredibly beautiful with long-lasting blooms, which draws enthusiasts toward them for the aesthetics.

Azalea Classification

Azaleas belong to the heath or Ericaceae family. They are part of the rhododendron genus. The plant is an evergreen shrub. There are more than 1000 species within the rhododendron genus and thousands of varieties and cultivars.

Azalea Description

Semi-cascading pink azalea bonsai

They make for incredible bonsai, no matter the shaping style.

©Meiqianbao/Shutterstock.com

Azaleas are an evergreen species, meaning they remain “alive” with green leaves year-round and don’t die off in the wintertime like some species (think maples that drop colorful leaves). They come in a wide range of varieties that change up their looks via color, leaf size and shade, branching type, and more, so specific descriptions are hard to come by without knowing the species you’re planting. They may also be styled in numerous ways, which also gives them a different appearance.

A general description of azaleas, however, includes these notes:

  • Azaleas are shrubs with many branches, sturdy trunks, and year-round green leaves
  • They range from upright to arches, often spreading with an almost rounded shape when left to grow naturally
  • Azaleas have different flower forms, some of which may come in 5 petals (least complex) to 12 petals in layered textures. The layered and the single crown varieties are both common and easy to find.
  • The colors of azalea blooms may be white, purple, pink, red, orange, yellow, burgundy, and bi-color. Often, you’ll find the bi-color varieties blend a dark shade with a pale shade, such as a white flower with a darker pink center.
  • Most species of azaleas are unscented, but they still attract pollinators.

Origins and History of Azaleas

Azalea bonsai with vivid reddish pink blooms

Azaleas tend to have vivid colored blooms, part of why they’re so popular.

©Walter Pall/Shutterstock.com

Rhododendrons and azaleas belong to the ancient plant group that evidence indicates dates back pretty much as far back as we can find. Fossil records reveal the flowering plant in early eras, long before records were written down, even. The flowering shrub is related to the rhododendron, but it’s also related to blueberries and pieris. The plants we think of today are descended from Asian shrubs that were originally cultivated by Buddhist monks. The flowering plant is the national flower of Nepal, is mentioned in ancient Chinese medical texts, and appears in ancient poetry in various texts.

Traditionally, the Japanese people divide the plant into two classes: Tsutsuji azalea which flower for 30 days after the spring equinox, and Satsuki, which flower about 30 days later than the equinox. The flowers were favored highly and exported to various parts of the world, with the first known appearance in Holland dating to 1680. After that, they spread to Germany, Belgium, France, and England, among other nations. Eventually, they were brought over to North America, though there are at least 26 known species of native plants in North America. Some of these include the flame azalea and the swamp honeysuckle, which were discovered in Alabama in the 1990s.

The plants are all over the world at this point, favored in many show gardens, botanical gardens, bonsai collections, backyards, and more. The wide range of colors, shapes, sizes, and types help to keep the beautiful plant popular in all its forms.

Varieties of Azalea Bonsai

There are many varieties and cultivars of azaleas that thrive as bonsai. Some of the most popular options include:

  • Satsuki azalea, Rhododendron indicum
  • Kurume, Rhododendron obtusum
  • Hiryu, Rhododendron obtusum
  • Chinzan
  • Eikan
  • Hakurei
  • Kaho
  • Osakasuki

The Satsuki is, perhaps, the most popular of all, particularly with Japanese bonsai enthusiasts. This species name refers to its blooming period between May and June, the fifth month of the Japanese lunar calendar.

How to Grow Azalea Bonsai

Small azalea in pot

Flowering bonsai produce tiny to huge blooms, depending on care and placement.

©Ilze Coertze/Shutterstock.com

Azaleas are one of the most popular bonsai species, thanks to their incredible beauty and variety of colors. Special care must be taken to protect and care for them properly, as noted below.

Planting Location

Azaleas need lots of sun, humidity, and protection from rain. This means that they do best in places where shade can be offered, some kind of overhang is available, and frost isn’t frequent.

Lighting

Most azalea species require full sun from spring to autumn for creating heavy flowering. However, some species can tolerate less sun and still thrive. Be sure to study up on your specific species to determine the best placement in regards to lighting.

No matter the species, though, they will need shade or a shade cloth in temperatures over 85 F, and at least 30% shade.

Temperature

If azaleas are in high humidity, they will handle heat over 100 F. If they’re in lower humidity, they’ll tolerate up to 90 F. On the lower range, they can endure temperatures down to just below freezing at 28 F, though ideally they will live where they are between 32 and 90 F.

If the plant will be in temperatures lower than 25 F, it’s best to bring them indoors or place them in a greenhouse to protect them from the cold. They will likely experience frost damage otherwise.

Watering

Deep red azalea bonsai

Placement is critical for care of azaleas.

©Alexandra Tyukavina/Shutterstock.com

Azaleas are prone to two issues concerning watering: over watering and under watering. This makes them a bit difficult to maintain properly.

They require moist soil and high humidity, but they cannot handle permanent wetness or sogginess. Always check the soil moisture before watering.

Tips for watering your azaleas:

  • Avoid tap water as the sole source of water for azaleas.
  • Instead, mix rainwater and tap water or use rainwater exclusively.
  • If need be, filter tap water if you cannot get a hold of enough rain water or you’re in drought.

Feeding

There are special fertilizers meant for azaleas and rhododendron species – these are the only ones you should use for your azalea bonsai. They should be applied weekly, if they’re liquid, and organic pellets should be offered less frequently. Follow the directions on the packages, as these are usually accurate for time periods. However, while the plant is flowering, reduce feeding to half the normal dose.

Pruning

A basal dominant plant, meaning azaleas’ lower trunk and body are stronger than the top, unlike most species in bonsai culture, azaleas should be pruned harder at the base than at the top.

The plant endures strong pruning and, in fact, thrives from it, producing new shoots from the branches that formerly had no leaves remaining.

Azaleas should be pruned immediately after flowering, by cutting or pinching by hand. This is also the best time for all other pruning and trimming, as this will help the next year’s development of buds and blooms and leaves.

Unwanted shoots and branches, however, may be pruned any time of year, but major styling is typically done in springtime, consciously omitting flowering.

Shaping

pink azalea bonsai

They may be shaped to look like traditional trees, left to grown more shrublike, or take on traditional bonsai shapes.

©irinacapel/Shutterstock.com

The tender bark and brittle branches of azaleas make them a bit more challenging to shape than others, for fear of damaging the plant. This means you should use soft aluminum wire, rather than harder wires like copper, and gently work with the plants to avoid damaging them.

Tips for shaping your azalea:

  • Use raffia or plastic tape to protect the plant as you work on shaping.
  • Make clean cuts with sharp tools to prevent wounds.
  • Seal any wounds with Lac Balsam or similar wound sealants immediately after any wounds may occur.
  • Remove all dead flowers from the tree immediately after flowering to prevent seed pods forming too soon. This will also encourage new leaf growth.
  • The most common styling for azaleas is root over rock, semi-cascade, windswept, informal upright, and slanting.
  • Azaleas may be trained as either twin or multiple trunk bonsai.

Wiring

Azalea plants may be wired but they are rather delicate. Use aluminum wiring for your azaleas to gently reshape them as desired, carefully taking your time as you wire. November in the Northern Hemisphere is the best time of year to do major wiring and shaping work on your azaleas.

Re-potting

Most experts advise re-potting your azalea bonsai every two years, during spring or after flowering. Prune back the roots carefully, disentangling them gently. Ensure the soil you use to re-pot is lime-free.

Common Problems of Azalea Bonsai

large pink azalea blooms on small bonsai

Some choose to leave azaleas unshaped to prevent damage.

©Chiara V/Shutterstock.com

Spiders

Thankfully, azaleas rarely deal with most pests. However, low humidity may encourage spider mites to take home in your azalea plants. If this happens, use gentle pesticides and increase the humidity of your azalea’s environment. This may mean you need to move the plant indoors for a time or invest in a greenhouse where the environment may be controlled.

Vine Weevil

Vine weevils and their grubs are rare but may cause harm to the azalea roots if left untreated. They should be eliminated with special pesticides or nematodes.

Root Rot

Because azaleas need high humidity, this is often translated incorrectly by inexperienced enthusiasts as over watering. Unfortunately, this will likely result in root rot, which can kill your plant.

Make sure you keep the growing medium moist but avoid letting it get soggy. You should also loosen the medium around the roots to free it up for proper drainage and possibly consider replanting into a container with better drainage if the issue seems persistent.

Leaf Galls

Azalea bonsai may also grow leaf galls, a type of fungus. This will turn the leaves pale green and may thicken the stems and curl them. A white powdery substance may also appear before the plant turns brown and hardens. The galls appear as nodules or lumps on the azalea.

Leaf galls result from over watering, as well, and typically appear on red and purple flowers more than others.

Remove the galls as soon as you see them and protect the plant from rain and faithfully check the soil to avoid over watering.

How to Propagate Azalea Bonsai

pink bonsai tree on blue and white background

Azalea bonsai thrive outdoors and indoors, depending on care.

©Bernd Schmidt/Shutterstock.com

Many species of bonsai, including jade bonsai, apple bonsai, and azalea bonsai are propagated through the use of cuttings or seeds. The cuttings should be taken in spring or summer and treated as other cuttings for propagation.

Azaleas are more easily propagated from cuttings:

  1. Select the parent plants that are healthy and vibrant.
  2. Irrigate the chosen parents for a few days before taking cuttings.
  3. In early morning, take your cuttings from the plants using clean, sterile pruners.
  4. Take the tips off branches, with at least 5 inches length to the cuttings.
  5. Use semi-hardened cuttings, meaning the wood cutting should be neither soft nor brittle, bending but not breaking. This type of wood occurs after spring growth when leaves are mature.
  6. Fill sterilized well-draining containers with rooting materials such as peat and perlite mixed.
  7. Trim the cut ends of your cuttings right below the leaf attachment point.
  8. Remove leaves from the bottom third of the cuttings.
  9. Remove all flower buds from the cuttings.
  10. Dip the cut ends into rooting hormone and insert the lower third of the cuttings into your growing medium.
  11. Gently water your plants and protect them with clear plastic, such as tops of bottles or growing tents, trapping in the moisture and humidity.
  12. Place the cuttings into a tray under bright, indirect light.
  13. Check the cuttings regularly to ensure the growing medium is moist but not soggy.

The cuttings should grow roots within about 2 months and will then be ready for planting.

Azalea Bonsai FAQs

pink bonsai on stand next to other potted plant

Bonsai trees may be tiny or medium in size, depending on the care and styling.

©StanOd/Shutterstock.com

Can azalea bonsai plants be kept indoors?

Azalea bonsai thrive outdoors! But technically, they may be kept indoors. It will be far more challenging, thanks to the plant’s natural needs for adequate sunlight, humidity, and proper air movement. If you are experienced or extremely dedicated, however, you may succeed keeping azaleas indoors.

How large do Azalea bonsai get?

The breadth and height of your azalea will vary greatly depending on the variety or species of tree you plant. Some may grow as tall as 4 feet and 3 feet in width, while others will be smaller.

How long do azalea bonsai live?

Each plant has a different lifespan due to a number of different factors. Some may have diseases or improper hybridization that stunt their lifetime, while others are bred are cared for properly and may live up to 100 years old or longer, with proper care.

This means your azalea bonsai could very well be an heirloom to pass to the next several generations.

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The photo featured at the top of this post is © irinacapel/Shutterstock.com


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About the Author

Sandy Porter is a writer at A-Z Animals primarily covering house garden plants, mammals, reptiles, and birds. Sandy has been writing professionally since 2017, has a Bachelor’s degree and is currently seeking her Masters. She has had lifelong experience with home gardens, cats, dogs, horses, lizards, frogs, and turtles and has written about these plants and animals professionally since 2017. She spent many years volunteering with horses and looks forward to extending that volunteer work into equine therapy in the near future. Sandy lives in Chicago, where she enjoys spotting wildlife such as foxes, rabbits, owls, hawks, and skunks on her patio and micro-garden.

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