Rainbow eucalyptus is a naturally occurring tree that grows in tropical areas and has a unique multi-colored bark. The varying colors and patterns on the trunk make it appear artificial, leading some to believe it must be a man-made creation or an elaborate hoax. However, rainbow eucalyptus is absolutely real and its colorful appearance comes from a distinctive feature of its bark.
What causes the rainbow colors?
The rainbow effect on rainbow eucalyptus trees comes from the natural shedding of the bark. As the outer bark peels away, it reveals the inner bark underneath that has a different color and texture. This process happens at different rates across the surface of the trunk, creating a streaked and mottled pattern of colors that shifts over time.
The shedding bark mechanism serves an important purpose for the tree. As the old bark peels away, chlorophyll that was in the outer bark layers is exposed. This allows the tree to continue photosynthesizing and producing food. The shedding bark also enables the tree to “breathe” and provide protection from pests and parasites trying to penetrate the inner bark.
Where do rainbow eucalyptus trees grow?
Rainbow eucalyptus is native to the Philippine Islands, Indonesia, and Papua New Guinea. It thrives in tropical environments with high humidity and rainfall. Some key facts about the native range of rainbow eucalyptus include:
- Grows at elevations between sea level to 2500 feet
- Requires annual rainfall over 100 inches per year
- Prefers humid conditions, no lower than 60% humidity
- Grows best in acidic soil with good drainage
Due to its need for tropical conditions, in the United States rainbow eucalyptus can only be grown naturally in parts of Florida, Hawaii, and California. The tree requires ample moisture and temperatures that never dip below 30°F.
| Location | Climate suitability |
|---|---|
| Hawaii | Ideal climate |
| Southern Florida | Suitable climate |
| Southern California | Marginally suitable climate |
| Other US States | Unsuitable climate |
Unique bark structure
In addition to its colorful bark, rainbow eucalyptus trees have some distinctive structural features:
- Smooth, multi-colored bark on trunk and branches
- Long strips peeling off larger sheets of bark
- New bark with bright green inner layers
- Older bark turns shades of blue, purple, orange, pink
- Leaves are 6 to 12 inches long, oval shape
- Produces small white flowers
The most vivid coloring occurs on young branches and at the top of older trunks. Lower down the trunk, the bark takes on more muted grey and brown hues. The constantly changing bark appearance makes it look like a painting in motion.
Myths and facts about rainbow trees
Because of its fantastical appearance, there are some common myths and exaggerations about rainbow eucalyptus trees:
| Myth | Fact |
|---|---|
| The colors are painted on | The colors occur naturally |
| Trunks are fully rainbow colored | Only the upper trunk shows vivid colors |
| Leaves change color | Leaves stay green |
| Grows anywhere | Requires tropical climate |
| Fast growing | Slow to medium growth rate |
| Stays small | Can reach over 100 ft tall |
While the bark has eye-catching hues, the leaves stay green throughout the year. The trees also take many years to reach their full height potential. Proper growing conditions are essential for the rainbow effect to emerge on the trunks.
Uses for rainbow eucalyptus wood
In areas where it can grow large enough, rainbow eucalyptus is harvested for its wood. Once cut and dried, the wood loses its colorful bark and takes on a more typical appearance. Uses include:
- Furniture making
- Flooring
- Turned wood products
- Musical instruments
- Pulp for paper
- Mulch and firewood
The wood is commonly compared to maple and is considered a hardwood. It machines well and turns smoothly on lathes. Fresh cut logs and lumber may still show some remnant streaks of color in the grain.
Where to see rainbow eucalyptus in the US
Since the climate range is limited in the continental US, truly thriving groves of rainbow eucalyptus are mainly found in Hawaii and Florida. Some locations to view these colorful trees include:
- Hawaii – Rainbow Eucalyptus Grove near Hilo on the Big Island of Hawaii
- Florida – Palm Beach Arboretum, Nokomis
- California – San Diego Zoo, Los Angeles Arboretum, Berkeley Botanical Gardens
- Texas – Houston Arboretum and Nature Center
- Louisiana – New Orleans Botanical Garden
Many arboretums and botanical gardens also showcase rainbow eucalyptus in outdoor tropical plant collections. The trees are often planted as specimen trees to draw interest from visitors.
Growing rainbow eucalyptus
For home gardeners hoping to grow rainbow eucalyptus trees, it can be challenging but is possible in the right climate. Here are some tips for successful cultivation:
- Start with a small tree or sapling from a nursery
- Choose a site with full sun and space for growth
- Prepare soil with lots of organic matter for drainage
- Water regularly during dry periods
- Apply mulch around base to retain moisture
- Fertilize with a complete fertilizer monthly
- Protect from frost and freezing
- Be patient – colorful bark takes years to develop
Potted rainbow eucalyptus can be grown as a container specimen in temperate climates. Bring the plant inside before temperatures drop below freezing. Provide ample water and humidity indoors.
Conclusion
With its extraordinarily colorful bark, the rainbow eucalyptus tree seems like something out of a fantasy world. However, it is absolutely real and its rainbow hues have a logical biological explanation. To experience these trees in their full glory requires a trip to the tropics. For those unable to travel to the native range, rainbow eucalyptus can still be admired in arboretums and botanic gardens with suitable climates to nurture them.
