How To Grow Rainbow Eucalyptus Bonsai | Growing & Care Guide

The Rainbow Eucalyptus is indeed an interesting plant known for its multi-color wood trunk. If you have ever seen the trunk, you would wonder if it is possible to recreate this tree in a smaller form. You can grow a Rainbow Eucalyptus bonsai!

Want to know what you need to provide to grow rainbow eucalyptus bonsai that are healthy? Here are the conditions necessary:

  • Adequate sunlight for over 6 hours, 
  • Well-draining acidic soil that is highly fertile
  • Regular watering to ensure moist soil
  • Medium to high humidity
  • Temperatures of 70℉ to 85℉, 
  • Weekly fertilizer with a special bonsai fertilizer 
  • Dedicated pruning and training 
  • Observation and treatment of pests and diseases  

Read on to prepare yourself better to grow a healthy rainbow eucalyptus bonsai with our step-by-step growing guide. 

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About Rainbow Eucalyptus 

The rainbow eucalyptus is native to the Philippines, Indonesia, and Papua New Guinea and can be found in other countries too such as Hawaii and Australia. You can also call it the Mindanao gum or rainbow gum. 

This eucalyptus gets its name from its rainbow-colored bark which peels off to reveal hues of green, red, gray, maroon, orange, and even purple!

In its natural habitat, it can attain a height of 200 feet! It can also adapt to many climatic conditions which makes it a popular tree, as well as a fast grower.

Is It Possible To Bonsai A Rainbow Eucalyptus?

Yes, it is possible to bonsai the famed rainbow eucalyptus tree!

By adhering to the following criteria such as watering accordingly, providing well-draining soil, repotting the plant from time to time, pruning, training, and providing enough sunlight. 

This eucalyptus tree grows in its natural state to 200 feet plus, and it is not realistic for you to think that you can dwarf it to a couple of inches. In reality, you could envisage a specimen of perhaps 3 feet. 

Continue and read through this blog to get more information about making a bonsai of the rainbow eucalyptus.  

Fast Fact: Temperatures, humidity, water, and airflow have a huge impact on the coloration of the tree rainbow eucalyptus bark.

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Growing Your Eucalyptus Bonsai From Seed

If you are fortunate enough to have rainbow eucalyptus seeds, you’ll understandably want to try your luck at growing them. So, to help you out, here are the steps to growing it. 

1. Procure Your Seeds

It is recommended to grow your own rainbow eucalyptus bonsai from seed in order to grow a healthy plant. Undoubtedly, there are many nurseries that can supply you with a sapling and if you decide to do that then go ahead. 

If saplings are unavailable, collect many seeds. It’s wise to have plenty of seeds as the germination rate for the rainbow eucalyptus is 50% to 60%. 

To germinate, the seeds need to remain moist. The seeds that germinate first are the best to grow.

2. Step By Step Germinating Rainbow Eucalyptus From Seed

  • Fill an empty bottle with room temperature water and add to it half a teaspoon of hydrogen peroxide, this helps to break down the hard exterior coating of the seed
  • Place the seeds evenly spaced out onto a paper towel
  • Dampen the paper towel 
  • Carefully fold the towel and place it inside a plastic bag. You can mark the date and details for future use
  • Keep checking the seeds as they should germinate after 4 days
  • If you start seeing any sprouted seeds you can pot them up in individual small pots
  • Water as per requirement when it is needed 

3. Potting Your Rainbow Eucalyptus Bonsai

To offer your bonsai the best chances of growing into a healthy bonsai, provide well-draining soil such as loam or sand amended with organic matter. 

Ensure the soil is of a slightly acidic nature as these plants do not take well to alkaline soils. Place your bonsai pot in a spot guaranteed to get a lot of sunlight. 

There shouldn’t be too much of a draft of air as humidity levels need to be high. 

4. Placement Of Your Bonsai Pot

Your eucalyptus bonsai is best placed outdoors as an outdoor bonsai grows better than an indoor one. Why you might ask. Well, this tree needs full sun, and unless you have a sunroom or greenhouse that receives at least 6 hours of full sun your bonsai will not thrive.

The morning sun is best for the foliage and the bark coloration. If your eucalyptus tree is in a container, it is very convenient to move around.

5. Pruning Your Rainbow Eucalyptus Bonsai

Pruning is best done in late summer rather than any other season. Also, pruning might lead to bleeding sap, which the warm dry weather will help to heal. If your tree has large wounds and it is of a smaller size, you can apply a dressing to help it heal faster. 

Avoid pruning when humidity levels are high as it can encourage diseases in trees.

6. Training Your Rainbow Eucalyptus Bonsai

In the initial years of growing your rainbow eucalyptus bonsai, making sure the plant stays relatively small is the biggest concern. You can do this by pinching growth as it gets too tall or wide. 

Eucalyptus bonsai trees are generally easy to train using wire. The wire should be in place for just enough time needed to train the bonsai. More time may cause the wire to create unpleasant imprints on your plant’s trunk. 

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Care for your Eucalyptus plants

Let us look at the factors for caring for your Eucalyptus plants

1. Location

Eucalyptus plants are known for their strong and deep roots that can crack and break through containers that are not rigid. That said, you will need a bigger pot, and a bigger pot comes with more weight. Placing the bonsai outdoors would help avoid needing to move this big and heavy pot!

Also, a eucalyptus bonsai needs a great amount of sunlight! You can best provide this to your bonsai when it is outdoors. 

2. Soil

This particular eucalyptus species prefers sandy, loamy soils that are fertile due to the presence of organic matter and are also well-draining. 

Eucalyptus bonsai does better with soils that are neutral to slightly acidic in pH levels. It does not appreciate alkaline soils and you shouldn’t use such soils. 

You can ensure the soil pH is correct by using a ready-made soil pH testing kit. 

3. Watering Routine

Water your rainbow eucalyptus bonsai well during its first year. These trees dislike being waterlogged or overly saturated. 

Keeping them moist will encourage the trunk and bark to swell, which encourages more color-defining stripes. Mulching helps keep in moisture, but be careful not to place the mulch up onto the trunk as an overly wet trunk will rot! 

4. Light 

Rainbow eucalyptus trees need plenty of Sun. So place your rainbow bonsai outdoors in a place where it will receive plenty of direct Sun. If there isn’t such a spot like this indoors, or on the porch, you will have to keep your rainbow eucalyptus bonsai outdoors.

5. Humidity

Like most bonsai plants, humidity is always a high priority. These plants are usually indoors and are prone to becoming dry if there is too little or too much air currents around the plant. Ensure there is a lot of humidity around your plant using a humidifier.

Allow the bonsai to be in an environment of high humidity.

NOTE- Watering is not a substitute for humidity! 

6. Temperature

Naturally, the rainbow eucalyptus is native to areas such as the Philippines, and Papua New Guinea. But, it is also found in Australia. It comes as no surprise that these trees are not tolerant of cold and frost. 

The rainbow eucalyptus tree does best in temperatures of 70℉ to 85℉ with good humidity. 

7. Fertilizer

Unless your bonsai has been potted up in particularly poor soil, your bonsai should not require fertilizer. Also administering fertilizer could speed up growth which goes against your aim, which is to keep them small. 

After the initial growth period, your bonsai will be fine with weekly fertilizing using a fertilizer specially made for bonsai plants. Avoid fertilizing too much during winter. 

8. Pruning 

When pruning a rainbow eucalyptus, you can remove the vertical buds anytime. However, you must wait for the lateral shoots to mature before cutting them off. 

Defoliate your eucalyptus anytime to ensure the leaves do not grow too big!  

This will promote the growth of smaller leaves. Use wire to influence the growth of your bonsai but be sure to remove it in time as the marks can last a long time and make for an unscenic sight! 

9. Diseases 

There is an endless supply of fungi and bacteria on the earth and many of them can find refuge in your rainbow eucalyptus bonsai! 


This is a fungus that causes discolored leaves and causes the wood beneath the bark to turn red-brown or dark brown. It is also known as the root, collar, foot, or crown rot.

Heart Or Trunk Rot

This is a fungus that kills the tree from within. By the time any symptoms like drooping branches are detected, the tree will be long gone and cannot be salvaged!

To treat and possibly save your bonsai from heart/trunk rot, you have to remove all the infected matter. But no guarantees it is enough! 

10. Pests

There are numerous insects that will be only too happy to undo the progress you have attained with your bonsai. Beetles, beetle borers, wasps, whiteflies, phyllids, and sharpshooters are attracted to the leaves of the rainbow eucalyptus bonsai.


There are several beetle species that can damage your eucalyptus tree, these are the eucalyptus snout beetle and the eucalyptus tortoise beetle. Adults and older larvae feed on the leaves of the tree resulting in ragged and notched edges on leaves. 

Heavy infestations of the bugs can nearly defoliate a tree!

Beetle Borers

This is the most common eucalyptus pest. The larvae form of this beetle tunnels into the layer just beneath the bark interfering with the supply of water and nutrients to the plant. 

The boring results in dried, wilted, branch dieback, and discolored foliage. Large infestations can kill a tree.


The eucalyptus gall wasp is a tiny wasp species whose larvae are laid on eucalyptus leaves and form raised galls on the leaves. You will notice slightly raised swellings on either side of the leaves about 1mm in diameter. It does not affect the tree’s health but looks unsightly!


Whiteflies are small white insects that hide on the underside of the plant’s leaves. They are not innocent and their presence shouldn’t be taken lightly!

These insects suck the sap of the plant and cause leaf damage as well as stunted growth. They are a vehicle for disease transmission. 


There are several species of phyllids that will sometimes attack the rainbow eucalyptus tree, but the Redgum Lerp Psyllid is the most notorious and damaging of them all!

Phyllids are minute insects that suck the juice from within the plant, this causes the leaves to drop prematurely. Severe defoliation can weaken the tree making it easy for other pathogens and other pests to enter and ultimately kill the plant as it is not able to carry out regular functions.  


Sharpshooters are a species of large leafhoppers that are pests. They secrete a sticky goo that does not cause lasting damage. 

The sharpshooters’ real damage occurs when they transmit a bacterium (Xylella fastidiosa) that can cause deadly plant diseases. 

When the sharpshooter feeds on a plant that is infected by the disease, it multiplies in the sharpshooter’s mouth. It is then transferred to another plant when the pest moves on to feed on another plant.


Wondering what it takes to grow a Rainbow Eucalyptus bonsai? Just a few conditions that replicate the natural environment of this tree. 

Adequate sunlight, fertile, well-draining, acidic soil, regular watering, medium to high humidity, temperatures between 70℉ and 85℉, weekly fertilizer, regular fertilizer, and observation for pests and diseases. 

Follow this guide well and you will have a healthy rainbow eucalyptus to show off! 

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How often do you water rainbow eucalyptus?

Rainbow eucalyptus should be watered regularly enough to keep the soil moist. You can feel the soil to check if it is moist enough or not. Based on this you can water your plants. But, generally, you can water your plant 2-3 times a week.