The Vetiver System
- March 5th, 2013
- in PROPERTY
Words and pictures by Scarlett Steer, Minines Plants
As environmental issues continue to dominate both agricultural and natural resource sectors, with soil erosion one of the most acute, it is comforting to know that steps are being taken to counteract the depletion of our precious reserves. And not only on a global scale, but right here in our own back yard.
Amid ever-increasing development on our islands, greener things are afoot in the BVI. Dr. Shannon Gore, Marine Biologist for the BVI Conservation & Fisheries Department, explains that the problem doesn’t lie with development itself, but how one goes about it. To this end, Dr. Gore is piloting a project to build community capacity to reduce island erosion, which includes creating a reference manual on best practices for reducing erosion on individual properties.
“This project,” explains Dr. Gore, “evolved through a number of events—dying near shore reefs, heavy sedimentation after rainfall, and slope failures to name but a few—that ultimately kept pointing towards a need for watershed management.” Dr. Gore goes on to mention that, as a number of the best practices included in the reference manual are not currently being observed, it was decided to add a working best practice example to the project by planting a “miracle grass”—otherwise known as vetiver—in a small area that experiences heavy erosion. “The use of this grass promises to provide landowners the opportunity to visually see one of the measures used in watershed management, and it’s potential for reducing runoff,” says Gore.
Although still relatively unknown in these parts, Dr. Gore’s project will not be vetiver’s first venture into the BVI. While it has to date predominantly been used in the stabilization of commercial earthworks such as roads and railways, it also features in privately owned landscapes across the BVI. Steven Steer, owner of Minine’s Plants and Landscaping on Tortola, says: “Vetiver is a highly valuable addition to your plant palate if your property faces possible erosion. It grows in pretty much anything, is drought tolerant, and is specifically good in properties that have been excessively de-vegetated. It is also cost-efficient.”
Getting a grip
“Vetiver? Isn’t that a folk band from the States?” A few frantic taps on a keyboard later and a friend produces a grainy clip of men with guitars wearing in brown corduroy with unfortunate facial hair (I can recommend their music though). Further digging unearthed a San Francisco Chronicle interview with founding member, Andy Cabic. When asked the origin of his band’s name, Cabic answered: “Vetiver is a grass. It has many uses.” While initially somewhat let down by this response (I mean come on Andy, you could have reached a little deeper), it can’t actually be faulted. Vetiver is quite something, and here’s a quick look at why:
Vetiveria zizanioides is a type of perennial grass, although just like bamboo, is considered a special member of the family. With an extensive root system and tall, densely clumped leaf blade it is perhaps best known for its effectiveness as a low cost soil and water conservation, erosion control, and environmental protection measure. Structurally it looks pretty much like lemongrass and keeps its leaves, which can be likened to those of sugarcane, up off the ground. Its stems, which act like the backbone of the erosion control barricade, are sturdy and woody—again like bamboo.
The unique characteristics of vetiver are as far reaching as its root system. It’s a fairly swift grower and can assume the role of unyielding barrier at only a few months old. Its seed does not germinate, nor does it spread by stolons or rhizomes to become a weed. Its crown lies beneath the soil’s surface, which helps to protect against over-grazing, hoof traffic, and fire. To date its leaves and roots have proven resistant to both disease and pests. Vetiver can also cope with a wide range of soil conditions and vastly varying climates. Since around 1987 the technology has been put to the test in the field in many countries—including Australia, Brazil, China, India, Indonesia, the Philippines, Indonesia, Madagascar, and Nigeria—in terms of soils and climates very much a mixed bag.
Of all these attributes, two are worth a revisit as they stand out as erosion and slope stabilization superstars. Vetiver’s vital, deep and immense root system is perhaps biologically the most significant and economically the most valuable. The roots are in fact as strong as—or stronger—than that of many hardwood species.
Secondly, vetiver grows vertically, forming a compact hedge of stiff stems able to withstand relatively deep water flow in just three to four months. This makes it adept at rapidly putting the brakes on rainfall run-off, as well as distributing it evenly. Hengchaovanich also observed that Vetiver can grow vertically on slope steeper than 150%.
Does vetiver have its drawbacks? Sure it does. “Aesthetically, Vetiver is often not what one looks for in a manicured landscape,” explains Mr. Steer, “as it can look a little untamed. But it has its place and, in our opinion, is an invaluable addition to many challenging sites in and around the BVI.”
We all know soil erosion means unhappy things like loss of land, reduced soil fertility, increased sediment flows, higher contaminants in diminishing water supplies, and increased hardships to both rural and urban populations. It’s a slippery slope, but just maybe Vetiver has it covered.