Plant a tree – but watch out for those figs!
Posted on Nov. 1, 2023 / Invasive Species / Subscribe 0
By: Ty McDonald
Arbor Day – in which individuals and groups worldwide are encouraged to plant trees – was first held in the U.S. in 1872. Though usually observed in the spring, Hawai’i celebrates Arbor Day in November, due to the mild temperatures and winter rainy season for most of the state.
Figure 1. A large ficus tree in all its grandeur, when given ample space both above and below-ground. Photo credit: andyoucreations.com/blog/banyan
Many folks recently celebrated the occasion by planting trees, but don’t worry if you missed out; it’s still a great time to plant a tree. If you have irrigation, it’s more or less always a good time to plant a tree in Hawai’i.
“The best time to plant a tree was 20 years ago. The second best time is today.”
- Chinese Proverb -
The list of benefits of trees to people is a long list and it can’t hurt to remind ourselves from time to time. Trees provide an excellent source of healthful nourishment in the fruits and nuts they produce, as well as emotional nourishment in products mankind derives from them, including chocolate, maple syrup and coffee beverages.
Trees provide both a practical and an aesthetic quality to the built landscape. Trees grown for shade can significantly cool both an indoor and an outdoor environment. Even in hot, sunny, makai areas of Hawai’i, one can gain significant relief simply by retreating under the canopy of a tree. This is especially true if the lowest branches have been removed, allowing for that slight, but savory, onshore breeze to waft by on its way upslope. Trees are also very effective as windbreaks, visual screens and sound barriers in the landscape.
Individual tree specimens, such as weeping willow (Salix babylonica) and monkeypod (Samanea saman), may evoke visual appeal through their shape, leaf texture and overall grace. Less subtle is the sensual splendor of brightly-colored flowering trees, especially those adorned with fragrant blossoms such as plumeria (Plumeria spp.). Whether enjoyed on the tree, gathered in an arrangement or strung into lei, flowers are a universally appreciated product of trees.
There are also many utilitarian benefits of the harvested tree that we garner daily, such as shelter, transportation, furniture, fuel, fiber, and paper. Some trees, such as the attractive and drought-resistant neem (Azadirachta indica), even have horticultural uses: a non-toxic insecticide derived from the leaves and seeds; and organic fertilizer (neem cake) from the seed waste.
"The best friend on earth of man is the tree. When we use the tree respectfully and economically, we have one of the greatest resources on the earth."
- Frank Lloyd Wright –
In terms of environmental benefits, trees are essential for human life on the planet. Forests are important in their positive effects on rainfall and watersheds. Trees (like all plants) provide the irreplaceable oxygen we need to breathe, and then literally clean-up after us by absorbing the carbon dioxide we exhale, converting it to more oxygen. In this light, wanton and reckless deforestation is acutely unwise at best.
Trees as super heroes
If that’s not enough to impress you, then there are heroic trees as well. Perhaps you heard the story that took place outside a courthouse on the U.S. mainland a number of years ago. A disgruntled client sought his own form of justice, attempting to shoot an attorney with a handgun. Luckily for the lawyer, a stout tree happened to be nearby and the victim used it as a shield until his assailant was subdued. I am sure that fella has a profound love of trees. So plant a tree, the life you save may be your own.
Right plant, right place
Once you are motivated to plant that tree, you must choose the type of tree and its location. These two important decisions should go hand-in-hand and may have the largest impact on future success. The mantra one hears over and over regarding landscape design is: “The right plant, in the right place.”
The significance of this plant selection tenet cannot be overstated, especially when considering trees. Due to size and cost of removal, it helps to be sure the home you pick for that spry little sapling will remain suitable as it grows into a mighty tree in the ensuing decades.
Figure 2. The aggressive surface root system of a banyan tree. Photo credit: Biologyeye.com
Large trees do have a place in the landscape, provided it is spacious enough to accommodate broad canopies and aggressive root systems. In Hawai’i, we often see examples of ill-placed specimens of fast-growing Ficus trees such as Weeping fig (F. benjamina), Moreton Bay fig (F. macrophylla), and Chinese/Malayan banyan (F. microcarpa). The banyans especially, are very successful competitors able to sprout out of rock walls, of all places. Eventually, the aerial roots reach the underlying soil and before long, the rapidly expanding tree engulfs the whole wall. Wow, that’s one impressive tree!
Strangler fig and related marauders
Strangler figs can refer to several large, fast-growing tropical fig species that sprout in crevices in tree trunks, slowly growing their aerial roots downward toward the ground. Eventually, they envelop their hosts in a lattice of thickened and fused roots which prevents the support tree from expanding in growth, ultimately leading to its demise.
Figure 3. (left) A strangler fig with a firm death grip on its host tree – Syzygium emilampra. Photo credit: Wikipedia
Figure 4. (right) Inside a hollow strangler fig tree well after the host died. Photo credit: Wanda von Bremen
I recall an old black-and-white photo in which a specimen of the renowned Florida Strangler Fig (F. aurea) was choking a tall, mature palm. The poor palm eventually died, not by constriction like you might suspect, but due to lack of sunlight.
That photo reminds me of another tragic “fig-related death” that occurred in Kona nearly 20 years ago. It was the fetid stench of decaying flesh emanating from a vacant condo that led authorities to the scene, where an otherwise good plant had gone bad.
Evidently, a renegade root from a nearby banyan had entered the condo between the foundation and a wall. The advancing appendage managed to “root out” and apprehend its prey: the refrigerator, and its freezer laden with sumptuous choice cuts from the nearby butcher shop.
The fated fridge was doomed and eventually yielded its life to the attacking root via an electrical short. However, the banyan burglar was unable to purloin the sirloin from the expired fridge because the frozen meat quickly thawed and soon enough revealed its slayer.
Amazingly, this is a true story. Apparently, the condo association does not believe in capital punishment, however, because the fig still lives, the fig lives, I tell you!
"A society grows great when old men plant trees whose shade they know they shall never sit in."
- Greek Proverb -
Ty McDonald is a University of Hawaii Extension Agent and advisor to the HILA board of directors.
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