The Rainbow Eucalyptus tree, Eucalyptus deglupta, is a visually striking species known for its vibrant, multicolored bark. Its trunk appears painted with an array of brilliant hues, captivating observers with its unique appearance.
Its Native Home
The Rainbow Eucalyptus is indigenous to tropical rainforests across Southeast Asia and the Pacific Islands. Its natural range extends through the Philippines, Indonesia (Sulawesi, New Guinea), and Papua New Guinea. This is the sole Eucalyptus species naturally found in the Northern Hemisphere. It grows from sea level to approximately 1,800 meters (5,900 feet) in these humid regions.
Growing Beyond Its Origins
Beyond its native habitat, the Rainbow Eucalyptus has been cultivated in other tropical and subtropical regions globally for ornamental and commercial purposes. In the United States, it grows in frost-free areas like Hawaii, Southern California, Florida, and Texas. In Hawaii, it was introduced in 1929 and now flourishes in arboretums and along roadsides. While it can reach 60 to 75 meters (200 to 250 feet) in its natural environment, cultivated trees typically grow to around 30 to 38 meters (100 to 125 feet).
Conditions for Thriving
The Rainbow Eucalyptus requires specific environmental conditions to thrive. It flourishes in warm, humid tropical or subtropical climates, necessitating a frost-free environment, with optimal growth occurring within a temperature range of 18 to 29 degrees Celsius (65 to 85 degrees Fahrenheit). The tree demands high and consistent rainfall, preferring consistently moist yet well-drained soil. It grows best in fertile, deep soil that is slightly acidic to neutral, with a pH between 5.6 and 6.0. Full sun exposure is also necessary for proper development, although partial shade can be tolerated, potentially affecting its growth and coloration; under these ideal conditions, the Rainbow Eucalyptus is a rapid grower, capable of adding 90 to 150 centimeters (3 to 5 feet) in height annually.
The Iconic Bark
The most distinguishing characteristic of the Rainbow Eucalyptus is its remarkably colorful bark. The tree’s smooth, orange-tinted outer bark continuously peels away in strips throughout the year, revealing a bright, neon-green inner bark underneath. As this newly exposed layer ages and is exposed to air and sunlight, it undergoes a transformation, gradually changing into a spectrum of colors including blues, purples, oranges, reds, yellows, and maroons. The initial green color is due to chlorophyll in the new bark, which then depletes as transparent surface cells fill with reddish-brown tannins, creating the vibrant array of hues. This continuous shedding and color change means that no two Rainbow Eucalyptus trees exhibit the exact same pattern.