Claire Hughes, a dear friend, called to ask me about gold trees, which are going OFF this year, along with other epic flowering trees: mango, ohia ai, lychee and more.
Gold trees were brought to Hawaii from tropical regions of South America and some were planted in Foster Botanical Garden. Plant pathologist Harold Lyon planted and nurtured a group of them in a grove there. Lyon was looking for trees to protect our watershed and prevent soil from washing into the ocean.
The scientific name for the gold tree as I learned was Tabebuia donnell-smithii, though recently, taxonomists have changed the name to Roseodendron donnell-smithii. Some put it in the genus Handroanthus.
DID YOU KNOW?
One way we can personally stem the rising tide of global climate change and extreme warming is by planting and nurturing big trees. Trees give off water vapor as part of their respiration. They shade the ground and cool the air. Tall trees even attract and capture water vapor. Every tree leaf is like a little factory making oxygen and giving off water vapor, cooling their environment in the process.
After akamai horticulturists noticed how pretty gold trees are, and observant landscape architects discovered their xeric (less thirsty) quality, more of the trees were planted in Hawaii. One such architect, the late Paul Weissich, was a longtime director of the garden and instrumental to the creation of the Halawa Xeriscape Garden, which is about to celebrate its 30th anniversary. (Save the date: Our annual Unthirsty Plant Sale and educational event will be at the xeriscape garden on Aug. 4.)
Weissich explained to me that the gold tree is extremely xeric because it originates from a tropical monsoon climate. A long, hot drought followed by rains results in blooms that explode with color.
Gold tree blooms are ephemeral, and individual blossoms are delicate. I love to see a pure halo of gold crowning the tree and the green lawn below carpeted with the glorious golden color. When blossoms float down from branches, they dance in the wind like graceful, golden-skirted ballerinas, twirling in the trades.
After enjoying the beautiful scene I rake the blooms to make a rich mulch and future compost, which nourish the soil and save water in the garden.
Myriad relatives of gold trees include silver trumpet trees, gold trumpets, purple trumpets, a mini white trumpet, pink tecoma and lavender-flowered jacaranda. Look at the tubular, trumpet-shaped flowers and you can see this relationship. These trees are all in the Bignoniaceae plant family. Another relative: the temperate-climate trumpet vine flowers.
Gold trees are great along streets and in parks. They are also fabulous on school grounds.
Richard Kapololu, a landscape architect with the state Department of Transportation, highly favored gold trees and planted many at the arid interchanges toward Ewa and the west side. He loved how, once well established in the ground, they are strong and tough.
As an aside, there is a botanical legacy at Hawaii public schools thanks to Paul Chang, who worked at Foster garden and then at the state Department of Education. Chang returned to the garden for seeds of “tough, flowering, drought-tolerant and native Hawaiian” plants. Careers related to trees runs in the family. Chang’s grandson George Cadd worked as a fabulous gardener and tree trimmer at the Hale Koa Hotel.
Gold trees can be grown from seeds, though they take some nurturing as seedlings and as young, transplanted trees. Many have been planted in our public spaces but not all of them have survived.
My husband, Clark Leavitt, and his crew have planted many gold trees. One, at the Makiki pumping station park, received some extra TLC. When we lived nearby, he would stop after work and give it some extra water. My parents and their dog-walking pals would also water it and recruited others to do so as well. Today, it is a happy, blooming teenage tree.
My friend Sandy Tsukiyama used to live in Brazil. There, gold trees are called “ipe amarelo” (“amarelo” means “yellow” in Portuguese). Spanish speakers call them “lapacho” or “primavera.”
The wood is gorgeous and useful for fine woodworking. I am not advocating cutting them down, but if you do, please save and make use of the wood. And save the seeds to plant more of these gorgeous, less-thirsty trees.
Heidi Bornhorst is a sustainable landscape consultant specializing in native, xeric and edible gardens. Reach her at heidibornhorst@gmail.com.
