Eucalyptus deglupta is cultivated as an ornamental tree , for planting in tropical and subtropical gardens and parks , commonly known as the rainbow eucalyptus . In the U.S . , rainbow eucalyptus grows in the frost -free climates found in Hawaii and the southern portions of california , Texas and Florida . It is suitable for U.S . Department of agriculture plant hardiness zones 10 and higher . In the continental U.S . , the tree only grows to heights of 100 to 125 feet . It is the only Eucalyptus species found naturally in New Britain , New Guinea , Ceram , Sulawesi and Mindanao . The unique multi -coloured bark is the most distinctive feature of the tree . Patches of outer bark are shed annually at different times , showing a bright green inner bark . This then darkens and matures to give blue , purple , orange , gray and then maroon tones .