Lessons from the Field
What vetiver users report: what works, why projects fail, and which claims to treat with care
Jim Smyle, TVNI’s President, screened discussions in vetiver Facebook groups during 2025 and 2026, with the help of an AI assistant, and compiled 78 reports from vetiver users in India, Latin America, Africa, the Caribbean, Asia and Australia. We then compared each one with the TVNI Guides and Design Standards. Most are successes, and many confirm, from real projects, what the standards say. The failures are just as useful: almost all of them trace to avoidable mistakes, not to the plant.
Our thanks to the many users whose posts are summarized here. Each report has a record number (for example VE-0024) in TVNI’s field feedback register. Many are single observations without a comparison plot, so we report them as users described them and say where the evidence is strong or weak.
What works: confirmed by users
Hedges that last a century
Contour hedges planted around 1926 still hold slopes of about 80%, with natural terrace risers up to 18 feet high, after decades without any care.
VE-0024, St Vincent and the Grenadines (Vonnie Roudette)
Slopes and infrastructure
A pylon foundation stable for 25 years, a coastal hill for 15, 65 km of Indian expressway embankment, dunes, stream banks and irrigation channels, all still performing.
VE-0020–0027, 0030: Venezuela, India, Costa Rica, Madagascar, Zimbabwe
More rain soaks in
A 400-day paired soil-column study found about three times more infiltration behind vetiver, with almost no runoff; a soil probe slid 1 m deep behind a two-year-old hedge.
VE-0028, 0029: India, Colombia
Cleaner water
Pond nitrate and phosphate fell sharply in Kenya; palm oil mill effluent COD fell 65% in Peru; a landfill leachate system in Australia has run for 23 years.
VE-0001–0006: Kenya, Peru, Ecuador, India, Australia, Venezuela
Pest control where it fits
A stem borer trap across about 270,000 ha of rice in China cut insecticide use by 70–80%. Root-knot nematodes enter vetiver roots but cannot multiply there.
VE-0065, 0068: China; global
Forage and mulch
Cut at 4–6 weeks’ regrowth for good forage. Regular pruning gives 2–5 kg of mulch per metre of hedge a year, stretching scarce manure much further.
VE-0077, 0078: Venezuela; global
These results match the TVNI standards for water margins, slopes, wastewater and farms. Farmers also report heavier tomatoes, earlier-flowering avocados, mangoes that survived a storm and better brinjal beside vetiver (VE-0045–0049). These are encouraging but informal, without comparison plots; the Global Vetiver Farmer Program is designed to measure exactly this.
Why projects fail
Almost never because of the plant. The failures reported to us share a handful of causes, all covered in the TVNI standards:
Poor or badly handled planting material
Slips kept three days in plastic bags, whole slips soaked in dung slurry, or cheap, shallow-rooted tillers bought on price alone (VE-0036, 0082). Use graded material and plant it fresh.
See DS-PLANT-QUALITY and DS-PLANTING
Wrong timing and no aftercare
Planting into a dry spell, no watering, weeds, cattle grazing and uprooting left one road slope “literally empty” six months after 150,000 tillers were planted (VE-0032, 0035).
See DS-PLANTING
Rows that are not on the contour
Decorative diagonal rows across a landfill slope channelled water and made erosion worse (VE-0033). Hedges must follow the contour to spread water, not concentrate it.
See DS-ON-FARM-SWC and DS-ENGINEERED-SLOPES
Contracts that pay for the wrong thing
Contractors planted twice the specified density because payment rewarded visible green and plant counts rather than a closed, working hedge (VE-0037).
Scale without skills
About 1,000 km of railway slopes in Venezuela were planted with the wrong design, untrained planters and no aftercare, and the failure discredited the technology nationally (VE-0031). Train first, start with demonstrations, then scale.
Lost institutional memory
A railway that had used vetiver later went back to machine-cut steps and geotextile once the people who knew the method moved on (VE-0034). Written standards and specifications keep the knowledge.
A simple fix that works: dipping roots in a microbial solution before planting raised survival from about 50% to 95% in South Africa, and careful handling gave 80–85% survival on a bare iron ore dump in India (VE-0040, 0041). See the Microbial Root Dip guide.
Limits and cautions
Some reports point to limits worth knowing. Several are single observations, and other users report different results, so read them as things to watch for rather than firm rules.
- Root depth: check how it was measured. One user in a dry part of India (550 mm rain) found roots only about half a meter deep after three years (VE-0038). Before drawing conclusions, ask how the roots were dug and how the grass was managed: many people stop digging at about 2 feet; regular shallow watering can keep roots near the surface; and hard grazing or repeated cutting in the dry season weakens the plant and its roots. Dry climates and hard subsoils can also limit depth. Where soils are deep and the hedge is well managed, roots go much deeper. TVNI’s slope standards design to a rooted zone of about 2 m.
- The stem borer trap does not suit every borer. It works only where the borer will lay eggs on a non-host plant, which excludes the rice specialist borers of India, the Philippines, Thailand and Indonesia (VE-0066). The China rice result cannot be assumed elsewhere.
- Vetiver beside young trees: mostly beneficial. One Indian user reported rodents sheltering in vetiver planted close to tree saplings and damaging their roots (VE-0060). This appears to be an isolated case: in Vietnam, where vetiver is widely planted very close to tree seedlings, there have been no reports of rodent damage, and in most cases the trees benefit from shade, wind protection and better moisture. If rodents are a known local pest, watch young trees closely in the first season.
- Cold and shade. Plants died at −10°C in Patagonia’s Bariloche, yet survived three winters farther south at Comodoro Rivadavia (VE-0039, 0044). Vetiver weakens in heavy shade; trials suggest about 60% shade is the limit, which matters in food forests (VE-0076).
- Glyphosate. Vetiver is very sensitive to glyphosate; in Argentina it was the first plant to show drift from night-time spraying (VE-0059). Keep herbicide well away from hedges.
- Vetiver oil is not a guaranteed income. Reported yields and returns vary widely, from under 3 liters of oil per hectare in Venezuela to much better returns elsewhere (VE-0079–0081). Check local markets before planting for oil.
- Planting material costs and supply. In some countries slips are scarce and expensive (US$5 each in Chile, with imports blocked: VE-0085). Local nurseries and vetiver service companies are the answer.
Claims not supported by evidence
These circulate online. They do harm when projects built on them fail, so please do not repeat them:
- “Vetiver makes water drinkable.” It does not. Vetiver is one useful stage in a treatment system, removing nutrients and some pollutants; it is not a source of safe drinking water (VE-0008, 0091).
- “Vetiver stores 30–40 tons of CO2 per hectare a year.” No source supports this. TVNI’s guidance on carbon storage is far more modest (VE-0090).
- “Vetiver can be sown from the air” and “its oil is made by bacteria.” The vetiver used for hedges is sterile and does not set viable seed; seeded types can become weeds. There is no evidence for the oil claim (VE-0092, 0093).
- Figures with no traceable source, including tables compiled by AI tools and single-source history or adoption claims (VE-0094, 0096). Ask for the original study.
- “Plant at scale without waiting for evidence.” This is how the largest failures happened (VE-0095, 0031).
Help us learn more
Many of the most interesting reports are single observations. The Global Vetiver Farmer Program, opening at the end of October 2026, will measure how vetiver affects the crops beside it on farms around the world. Please take part, and keep sending your results, good and bad, to [email protected]. Personal stories are welcome on Stories and Testimonials.