Gardeners' Dirt: Rainbow eucalyptus tree a living work of art
By Debbi Roskey - Victoria County Master GardenerEdited by Charla Borchers Leon
April 19, 2012 at midnight
Updated April 18, 2012 at 11:19 p.m.
Editor's Note: The material published in this column usually shares recommended plants and good gardening practices for this area. On occasion, an author chooses to write an article about a plant found to be especially attractive or interesting, but not necessarily proven to survive here. While eucalyptus trees have been known to grow locally, they are freeze sensitive and not particularly adapted to this area.
Have you ever seen or heard of a rainbow eucalyptus tree? The first time I saw one, I was awestruck. It looked as if a child had gone crazy with crayons, coloring the trunk and limbs in beautiful, different colors.
Where in the world?
First glimpse of a real rainbow eucalyptus tree might actually be in Hawaii - if you are lucky to visit there. I know of them to be particularly prevalent on the Big Island of Hawaii as I have relatives in Pahoa.
The rainbow is unique among the eucalypts. Unlike other members of the genus, the rainbow hails from the Philippine Islands, specifically the island of Mindanao, and that is why the tree is also known as a Mindanao gum. E. deglupta was introduced to the Hawaiian Islands in 1929.
Where in the U.S.?
This beauty is a humid tropic grower and has been grown successfully in south Florida and southern California. It is said to exist as far north in Texas as Richmond, but extra care and diligence is required.
All other locations may result in winter death of the tree, as this tree can only withstand light frost and cannot survive a hard freeze.
Risky in freeze
Remember the winter two years ago, when the temperature dropped into the teens for several nights? January to February 2011 also showed us a few freezing nights, although this past year was not so cold.
As this tree is not freeze tolerant and can reach heights up to 220 feet (compared to our oak trees at 30-40 feet high) in an ideal environment, container growing would be almost impossible. If struck by a long hard freeze, imagine the effort and cost of having to remove a dead tree of such height from your premises.
Predicting the weather has had huge advancements, but there is also a wide margin for error. So, growing this tree in our area is risky and not advised, but if you are a risk taker, its beauty might be worth a gamble.
Stages of color
This gem gets its common name from the striking stages of color on its trunk and limbs. While these colors resembling stripes of a rainbow are vivid and look painted on, the ever-changing hues are entirely natural. Mother Nature is quite the artist.
Unlike other trees, like oaks, the rainbow doesn't have a thick, corky layer of bark on the trunk; instead, the bark is smooth and vibrantly alive, and as it grows, it exfoliates thin layers of spent tissue. This occurs in irregular zones, at different times.
Colors darken before exfoliation
Once the layers come off, they reveal new and fresh green bark. As the newly exposed bark slowly ages, it changes from bright green to dark green, then bluish to purplish and then pink-orange.
Finally, the color becomes a brownish maroon right before exfoliation occurs. Since this happens at different zones of the trunk and in different stages simultaneously, the colors are varied and almost constantly changing. As a result, the tree will never have the same color pattern twice, making it appear to be a living work of art.
Most eucalyptus have a poignant minty, pine scent with a touch of honey - the kind that reminds us of medicinal use - and is unappealing to some.
The rainbow eucalyptus, however, produces none of the familiar aromatic oils that other eucalypts do, which is a bonus to those who desire a less fragrant smell. Commercial uses for this tree include pulp, paper and lumber.
Option is yours
This tree is an amazing tribute to nature. It is a wonder to behold and can add a magical dimension to any landscape.
Unfortunately, the outcome of planting one in our area may be short-lived, as when a hard freeze does occur it will likely freeze the exterior branches, requiring extensive pruning to remove the dead wood or it may be totally lost with the first hard freeze requiring complete removal.
But then, we are constantly facing challenges and as long as you know this going into it, the option is yours. Just remember that while its beauty is more than attractive, it is a living work of art that could more than likely freeze in our area.
The Gardeners' Dirt is written by members of the Victoria County Master Gardener Association, an educational outreach of Texas AgriLife Extension - Victoria County. Mail your questions in care of the Advocate, P.O. Box 1518, Victoria, TX 77901; or firstname.lastname@example.org, or comment on this column at VictoriaAdvocate.com.