The Vetiver Network International (TVNI)

Vetiver Grass Technology

What it is, how to grow it, and how to design with it

If you have a land or water problem, there is a good chance Vetiver Grass Technology can fix it.

The low-cost Vetiver Grass Technology (VGT) uses the deep-rooted, non-invasive vetiver grass (Chrysopogon zizanioides) to control soil erosion, stabilize slopes and rehabilitate degraded land. Developed and promoted globally since the 1980s, VGT mainly involves planting vetiver in dense, narrow hedgerows along the contour. Its vertical roots, reaching 3–5 meters within two to three years, and its dense, stiff, filtering hedge above ground anchor the soil, slow runoff and trap sediment. It thrives in harsh conditions including drought, flood and poor soils, making it ideal for agriculture, infrastructure protection, phytoremediation of contaminated soil and water, disaster mitigation and environmental restoration. Beyond this core group of applications, vetiver also offers economic products and benefits through essential oils, handicrafts, pest control, forage, mulch and high rates of carbon sequestration, among others.

Vetiver-stabilized slopes and terraced farms along a railway line in Madagascar — Rehabilitation of a cyclone-damaged railway in Madagascar using vetiver to repair and stabilize batter and fill slopes along the line, with vetiver also used to stabilize, conserve and improve the farms alongside it. See: Vetiver Victorious – the Systematic Use of Vetiver to Save Madagascar’s FCE Railway

Water is the master function

Strip Vetiver Grass Technology back to its core and it is a way to manage rainfall: where the rain goes, and how it moves across and into the land.

A dense vetiver hedge works as a porous weir. It does not dam water; it meters it. Runoff arriving at the hedge is slowed, ponded briefly, spread along the hedge and passed through the stem base at low velocity, dropping its sediment on the upslope side. Below ground, the deep root wall draws that water down into the soil. Get the water right and water-driven erosion is largely solved as a by-product, because erosion is the symptom and moving water is the cause. This is why one plant serves erosion control, groundwater recharge, slope stabilization and pollution control: in every case it is managing water, and the application only changes what we want the water to do.

Cross section of a slope showing a vetiver hedge as a porous weir: fast runoff arrives from upslope, slows and ponds briefly behind the hedge where sediment settles and builds a terrace, spreads along the hedge and passes slowly through the stem base, and soaks deep into the soil through the root wall. — The porous weir. A dense vetiver hedge does not dam water; it meters it. Above ground it slows, ponds, spreads and releases runoff; below ground the root wall draws water down into the profile. As sediment builds up, new crowns form higher on the stems, so the crest rises with the deposit and the hedge becomes a terrace riser instead of filling up. (Tap the diagram to enlarge.)

Vetiver and Water (PDF)Vetiver Hedge Mechanisms Read more

The pages below give an overview of Vetiver Grass Technology, followed by the basics. Anyone using vetiver for the first time should read them in this order.