Rainbow Eucalyptus Bonsai [In-Depth Bonsai Guide]

Rainbow eucalyptus (Eucalyptus deglupta) is an evergreen tropical tree that is native to the Philippines and can reach over 300 feet high and 6 feet wide. The Rainbow Eucalyptus, also known as Rainbow Gum, is a tree that can be made into bonsai with the proper care.

Mature Rainbow Eucalyptus
Rainbow Eucalyptus tree in Maui island, Hawaii

Its beautiful colors emerge when the tree is approximately half an inch thick. Contrary to popular belief, the tree’s bark is not vibrant. The tinted wood beneath the bark is revealed when the thin bark is removed. 

Although they may not be the best option for beginners, rainbow eucalyptus bonsai can be great for large, tropically-climate specimens.

Rainbow Eucalyptus Overview

Scientific NameTrade NameHeight (mature size)Bonsai heightSunlight
Eucalyptus degluptaRainbow Gum 250 feet+3-7 feetDirect Sunlight

Rainbows are tropical trees that have adapted to living in a rainforest environment. Although they tend to grow slower in cooler winters, rainbows can still retain their leaves all year. 

Rainbows must be protected against freezes, they cannot survive light frost conditions for short periods (contrary to popular belief).

Rainbow Eucalyptus Bark

These trees are most active in summer when they can display their strength and speed of growth. These trees can grow up to eight to ten feet during a single growing season and more if they are well cared for. These growth rates are wonderful for bonsai purposes because they allow frequent pruning to thicken the trunk.

Its striking color stripes on the trunk and limbs of the tree give it its common name. Although they appear painted, the ever-changing colors of rainbow eucalyptus trees are a natural feature. 

Rainbow eucalyptus is not like other trees, such as oaks. It doesn’t have a thick layer of bark that is hard and corky on its trunk. Instead, the bark is smooth, vibrantly alive, with thin layers of exfoliated tissue as it grows. This happens in different areas at different times. The layers are removed, and new, fresh green bark is revealed.

As the bark is exposed, it becomes darker, bluish, purplish and pink-orange as it ages. The color turns brownish-moonlight after exfoliation. The colors change in this way are constantly changing because they occur simultaneously at different stages and zones on the trunk.

The tree will never be the same color twice, which makes it a living work of art.

Rainbow eucalyptus needs water, especially when it’s young. This tree will grow slower if there isn’t enough water. The exfoliation will take place in smaller dots than long strips. It should not be allowed to dry out in containers.

how to grow a rainbow eucalyptus bonsai

To thrive, your tree will need plenty of water. For best growth, keep the soil moist but not too wet. To keep your plant small, trim off the top and sides shoots. 

General Eucalyptus Growth

Eucalyptus trees can grow up to a foot per month. If you’re diligent about pinching back, a bonsai that is three feet tall can be achieved.  Eucalyptus trees have large leaves. Careful pruning can help keep them balanced and encourage a smaller leaf size.

Step 1: Seedlings

Seeding is the best way to start a Rainbow Eucalyptus bonsai. You should buy enough seeds to ensure a good germination rate. After the seeds are fully dried, they can be placed in the sun. They should germinate within three weeks. The best seed to start bonsai is the one that has shown progress.

Germination tips

Expect a die-off of at least 50% when germinating Rainbow Eucalyptus seeds.

 Your chances of germination are improved by soaking your seeds overnight. Sow your seeds mid- to late in the spring. A hot summer is the best time to harden your saplings for a rainbow eucalyptus bonsai.

Keep your seedlings hydrated during germination. 

Germination can take as long as three weeks. Your best bonsai candidates will often be the first to emerge. Monitor their growth rate to affirm if they are the strongest seedlings.

For success, it is essential to incubate your seedlings. 

After their first transplantation, you can begin incubating them immediately. Put them in a plastic container and place the box in a cool, shaded area that doesn’t get too hot. Allow them to rest for at least a week. Water as often as necessary. They might appear to be wilting and even dead at first. The best candidates will come back. After a week, remove the box from the sun and begin acclimating them in full sunlight for three weeks.

Step 2: Saplings

Once approximately 6 inches and above, your Rainbow Eucalyptus is considered a sapling. At first, keep them in a shady spot that is not in direct sunlight. Gradually increase the sun exposure. It is important to water your bonsai regularly until it establishes its roots. 

There are several stages of growth for Eucalyptus trees. 

Your saplings will begin to grow quickly after the first month. You must be diligent in reducing growth otherwise, the trunk will remain skinny and never achieve the proper bonsai aesthetic.

Step 3: Planting

When your sapling is approximately ten inches tall, it is ready to be placed in its final growing pot. 

Rainbow eucalyptus bonsai can grow fast.

Be careful when choosing a container, as it will most likely be the container for the Rainbow Eucalyptus for a few years. Choose a 20-inch pot to allow your plant’s roots space for the typical eucalyptus growth. 

A bonsai’s best friend is quality soil. Give it plenty of organic matter to encourage growth.

Step 4: Outdoor Care

Rainbow eucalyptus Bonsai are tropical and will not tolerate cold winters. 

They can be grown outdoors in zones 9 through 11, but they will require special care if the outside temperature drops below 55 degrees. 

It will not grow well if it is brought inside. To keep the roots warm, wrap straw or mulch around them. If you experience colder temperatures, place your rainbow eucalyptus bonsai in a covered shelter that receives direct sunlight year-round. The best option is an outdoor greenhouse or conservatory. Rainbow Euclptyus bonsai artists often over-winter their plants in a greenhouse and cover their soil with 5 inches of extra bonsai soil for added insulation.

Step 5: Pest Protection

Rainbow eucalyptus is generally pest-free. Although there are occasional mealybugs and aphids that may be present, the tree can still be grown without too much concern. Mycorrhizal Inoculum should be applied to plants, particularly in areas that have been heavily disturbed.

Unique Bark

One feature that makes these trees easily identifiable is their multi-colored bark. Their multi-colored bark is what makes them distinctive. They have different colors underneath their bark, and the flaky barks that fall when they grow taller are revealed.

The barks show light red, green, orange, and purple streaks.

These colors earned them the Rainbow Eucalyptus name. This tree is a popular Eucalyptus species, and many people plant it for its unique characteristics. 

Fun Facts

  • Eucalyptus deglupta (Rainbow Eucalyptus), hails from Mindanao’s rainforests. Mindanao is the easternmost and southernmost island of the Philippine islands group.
  • The Rainbow Eucalyptus doesn’t produce the aroma oils that other Eucalyptus are famous for.

Where to Buy Rainbow Eucalyptus

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