Indonesian gum (Eucalyptus deglupta)
The spectacular Eucalyptus deglupta, or Indonesian gum, is a giant, fast-growing evergreen prized for its continuously shedding, multi-colored trunk bark.
Complete Plant Information
Overview
The Eucalyptus deglupta, commonly known as Indonesian gum or rainbow eucalyptus, is one of the most visually dramatic trees suitable for tropical and subtropical landscapes. This very large, fast-growing broadleaved evergreen is native primarily to areas of high rainfall in New Guinea, Indonesia, and the Philippines, holding the unique distinction of being the only eucalyptus indigenous to the Northern Hemisphere. Its magnificent peeling bark, which reveals streaks of green, red, orange, and brown, gives the Rainbow eucalyptus its famous common name.
As a rapid grower, the Indonesian gum can quickly establish massive size, reaching 100 to 250 feet tall in ideal native conditions, though it remains substantial outside these areas. It demands consistent moisture and unfiltered light, making it a cornerstone specimen tree where hardiness permits. Beyond its sheer scale, the stunning visual appeal of its trunk makes the Eucalyptus deglupta an unparalleled focal point in large estates or public plantings.
Gardeners must recognize its specific climate requirements; this magnificent tree is intolerant of frost and thrives only in the warmest USDA Zones 10 through 11. When its conditions are met—rich, wet soil and relentless sun—its maintenance remains surprisingly low, offering substantial, year-round tropical impact.
Fast Facts
- Plant Family: Myrtaceae
- Plant Type: Tree
- Native Range: Malesia and Papuasia
- Hardiness Zones: USDA Zones 10-11
- Size at Maturity:
- Height: “100-250 ft”
- Spread: “60-125 ft”
- Bloom Time: Seasonal bloomer
- Bloom Description: White
- Sun Exposure: Full sun
- Water Needs: Medium to wet
- Maintenance Level: Low
How to Grow
Planting the Eucalyptus deglupta should occur during consistently warm periods when soil temperatures encourage robust root development. Locate this tree far from structures, as its root system will seek out its preferred rich, medium to wet soils. Successful establishment is contingent upon the availability of full sun throughout the day; even partial shade can inhibit both growth rate and the development of colorful bark.
Watering is critical for this species, which originates in humid, high-rainfall environments. While established trees require medium to wet soil conditions, ensure that drainage is adequate to prevent stagnation, even though they tolerate significant moisture. Outside of heavily tropical, non-freezing climates, supplemental irrigation is required to mimic its native environment.
The maintenance level for the Indonesian gum is generally low once established, as it naturally sheds debris. Be aware that it is intolerant of frost; any hard freeze will likely severely damage or kill young specimens. In areas bordering Zone 10, protect young trees if frost warnings are issued, though container growing is generally impractical given the mature size of the Eucalyptus deglupta.
Landscape Uses
The primary functional roles for the Indonesian gum involve providing massive scale and shade in appropriate environments. Where zones 10-11 are guaranteed frost-free, it excels as a huge landscape tree capable of defining open spaces. Its value as a street tree, particularly noted in locations like Hawaii, stems from its vertical growth habit and its capacity to offer dense overhead canopy.
Due to its immense eventual size and rapid initial growth, the Rainbow eucalyptus generally requires no companions competing closely for root space or light. It functions best as a solitary specimen or in very large, established woodland borders where its size can be fully appreciated. Its aesthetic appeal is focused entirely on its trunk, meaning it should be planted where the smooth, colorful bark can be viewed year-round from pedestrian areas or roadsides.
Standout Features
Flower Qualities
- Showy
Noteworthy Characteristics
Eucalyptus deglupta, commonly called Mindanao gum or rainbow eucalyptus, is a very large, fast-growing, broadleaved evergreen tree that is native to moist humid tropical forested areas with high rainfall in New Guinea, Indonesia and the Philippine Islands (Island of Mindanao). It is the only eucalyptus tree that is indigenous to the northern hemisphere. In its native habitat, it will mature to as much as 250’ tall with a trunk diameter of 6’. Outside its native habitat, it will typically grow much shorter (to 100-125’ tall). It is perhaps best noted for its smooth orange-tinted trunk bark which peels in summer to reveal a unique and sometimes stunning multi-colored bark (as described by the common name of rainbow eucalyptus) consisting of streaks of pale green, red, orange, gray and purple-brown. Outside tropical settings, the bark is typically much less colorful.
Tolerances
Potential Problems
Generally, the Eucalyptus deglupta exhibits excellent resistance, reporting no serious insect or disease problems under optimal growing conditions. This low maintenance profile contributes significantly to its appeal in suitable climates. If growth appears stunted or leaves brown prematurely, the cause is overwhelmingly likely environmental stress, such as insufficient water or exposure to cold temperatures.
Frequently Asked Questions
What hardiness zones is Indonesian gum suitable for?
The Indonesian gum shows winter hardiness only in USDA Zones 10 through 11, as it is intolerant of frost.
How large does Eucalyptus deglupta grow?
In its native habitat, Eucalyptus deglupta can reach heights of 250 feet, although cultivated specimens often mature closer to 100 to 125 feet tall with a spread between 60 and 125 feet.
What sun exposure does Eucalyptus deglupta need?
This imposing tree demands full sun exposure to achieve its best growth and display the characteristic peeling bark for which the rainbow eucalyptus is famous.
When does Indonesian gum bloom?
The Eucalyptus deglupta is a seasonal bloomer, producing tiny white flowers at various times throughout the year depending on its precise location.
Conclusion
The Eucalyptus deglupta offers unparalleled architectural drama and color year-round, making the Indonesian gum a treasured specimen where warm climates allow. Its rapid growth and low pest pressure provide significant aesthetic returns for minimal recurring effort. Before planting this massive tree, confirm you are in USDA Zones 10 or 11 and have ample room to accommodate its 125-foot spread.
companion planting with tropical species
When designing a landscape around a specimen like the Indonesian gum, select companion plants that share its requirement for high moisture and full sun. Broad-leaved tropical understory plants like large native ferns or philodendrons can thrive nearby, provided they are kept clear of the main trunk area where the roots need access to consistent wet soil. Avoid shallow-rooted turfgrasses directly under the canopy if you wish to maintain the damp, rich soil conditions this eucalyptus prefers.
design ideas for maximum visual impact
To maximize the visual impact of the rainbow bark, incorporate landscape uplighting strategically. Position spotlights at the base of the trunk, aiming upward, especially in areas visible after dusk. This technique dramatically highlights the streaks of color on the Eucalyptus deglupta bark, turning the tree into a dynamic feature throughout the evening hours. Remember that the coloration will be most intense in actively growing, humid, tropical settings.
