(updated August 5, 2026)
This package is a suite of generic design standards and guides for Vetiver Grass Technology, grounded in research, long-term field experience and, where applicable, current engineering practice. It exists because the global spread of VGT created a need for consistency. The standards give practitioners design and implementation guidance, help agencies, consultants and contractors prepare contract-ready documentation, and set minimum technical requirements for design, plant material, installation and quality assurance.
They are deliberately generic. VGT is a nature-based technology, and local soils, climate, hydrology, effluent characteristics and regulation all shape how it performs. Adapt them to your site, your regulatory framework and your project objectives. Do not apply them rigidly.
Every module contains a table of contents and a reference list supporting its design logic. Links point to Google Drive; internal table-of-contents links work only once the file is downloaded.
Start here
| Vetiver Hedge Mechanisms (v3 -new)— above ground, below ground, structural, operational and solute roles. The physical and biological basis for everything else in the package: how a hedge slows water, spreads it, builds terraces, reinforces soil and moves nutrients. Read this before choosing a module.
Vetiver Planting Guide — planting instructions covering nearly all applications. Plant material, root and shoot trim, crown depth, spacing, firming and gap-filling. |
Background reading — the science behind the standards
| Vetiver Roots: The Vetiver System Technology Hidden Half — Dr. Paul Truong, The Vetiver Network International, 2022, 173 pp.
Paul Truong has done more than anyone to put the Vetiver System on a measured footing, and this book is where the belowground half of that work is gathered. It is not a design standard and does not tell you what to build. It tells you why the standards say what they say. It covers root growth, distribution and lifespan; root responses to flooding, drought, salinity, aluminium toxicity and heavy metals; penetration of compacted and mechanically resistant soils; interactions with soil organisms including mycorrhizal fungi; and the principles of slope stabilisation, with their limits stated. It is also extensively photographed — root excavations, roots driven through compacted dam walls, shaded against open-grown plants, root systems at depth — a visual record of the hidden half that exists nowhere else and is worth the download on its own. A concrete measure of its value rather than a compliment: reading it systematically produced version 2 of the Mechanisms standard, which withdrew an apparent root cohesion figure the manual had carried since its first revision, corrected two statements, and added five new items to its register of open questions. Very few reference works earn their keep that visibly. |
Choosing a module
Modules are grouped in four domains — A water and hydrological protection, B slopes, earthworks and geotechnical stability, C wastewater, effluent and pollution control, D livelihoods, products and community systems. Work from the problem, not the domain:
| Your problem | Start at |
| Canal, river or stream bank erosion | A1, A2 |
| Gully head-cutting and channel loss | A6 |
| Reservoir or dam draw-down zone, fluctuating water level | A3, A4 |
| Farm-scale soil and water loss | A5, D3, D12 |
| Shallow slope or embankment failure | B1, B2, B4 |
| Failed or reactivating slope | B2 |
| Works on Vertisols (black cotton soils) | B5, D12 |
| High-strength wastewater — coffee, POME, landfill leachate | C1, C4, C5 |
| Raw sewage | C2 |
| Polishing treated effluent to a compliance standard | C3 |
| Urban stormwater at plot scale | C6 |
| Lake, tank or reservoir pollution | A8 |
| Community income and adoption | D1, D2, D9, D13 |
| Soil biology, pests, nematodes, forage | D4–D8 |
Many sites need more than one module. Common pairings: B1 + C5 for landfills; B1 + C2 for sewage lagoons; A6 + A5 for degraded catchments; A3 + A4 for hydropower reservoirs; any C module + D1 for community-run systems.
Data to gather before you design
| Hydrology | Geotechnical | Effluent (C modules) | Site constraints |
| Rainfall intensity and seasonality; runoff patterns; water-level fluctuation (A3, A4); effluent volumes and loading rates | Slope gradient and height; soil type and shear strength; seep lines or perched water; stability history | COD and BOD; ammonia, nitrate, phosphate; pH, EC, salinity; oil and grease (POME) | Available land; access for planting and maintenance; regulatory offsets from gas lines, geomembranes and similar |
What VGT can and cannot do
Common causes of failure
Across global experience, failures come from a short and repetitive list. Each module’s design envelope carries its own risk notes; these are the ones that recur everywhere.
- Glyphosate drift. It kills vetiver outright. Keep a 2 m no-spray corridor and settle this at design stage, not in year two. Decisive where VGT is proposed alongside herbicide-based conservation tillage.
- Shade. Deep shade suppresses growth severely. Note that shading an already-established hedge is more damaging than establishing under shade, so agroforestry and orchard designs must consider canopy closure years ahead.
- Abrupt transfer into saturated ground. Vetiver does grow in waterlogged anaerobic soil, but it takes roughly three weeks to build the aerenchyma that oxygenates its roots there. Dryland-raised material set straight into standing anaerobic mud is at risk through that window. Stage the transition, or use material already raised wet. This is an establishment constraint, not a species limit — and it is the likeliest origin of the belief that vetiver cannot take waterlogging.
- Incorrect spacing, density or alignment. Off-contour alignment destroys the spreading function, which is the mechanism most field results depend on.
- Poor maintenance in the first 8–12 weeks. Includes livestock access before the hedge is established, and cultivation too close to the line.
- Overloading evapotranspiration or treatment systems. Loading beyond design capacity.
- Planting on active landslide zones. Drainage control comes first.
- Ignoring hydrological pathways. Especially seep lines.
The modules
A — Water and hydrological protection
| Code | Module | What it addresses |
| A1 | Canal Bank Stabilization | Stabilizes canal embankments; reduces erosion and desilting |
| A2 | River and Stream Bank Buffers | Protects riverbanks; filters sediment from riparian inflow |
| A3 | Draw-down Zones and Fluctuating Water-Level Systems of Dams and Reservoirs | Stabilizes fluctuating margins; resists wave action; tolerates periodic submergence |
| A4 | Floating Islands (pontoons) | Nutrient removal in open water; reduces algal blooms |
| A5 | Farm Soil and Water Conservation | Conserves soil and water; increases infiltration; reduces runoff |
| A6 | Gully Rehabilitation | Arrests head-cutting; stabilizes sidewalls; reduces sediment export |
| A7 | Flower Industry — water quality, compliance and environmental resilience | Kenya case study; effluent and compliance framework for cut-flower operations |
| A8 | Lake, Tank and Reservoir Pollution | Integrated approach to pollution in standing water bodies |
| A9 | Retrofitting Watershed Infrastructure in Four Global Regions | Folder of six files: introduction, hedge dynamics, Africa, Asia, Latin America, USA |
B — Slopes, earthworks and geotechnical stability
| Code | Module | What it addresses |
| B1 | Slope Stabilization (infrastructure) | Engineered slopes; increases shear strength; prevents shallow slips |
| B2 | Landslide Repair | Stabilizes failed slopes; improves drainage; reduces reactivation risk |
| B3 | Embankment Stability | Strengthens embankments and berms; reduces seepage |
| B4 | Engineered Slopes — integrated bio-hydro-mechanical stabilization | Combines vetiver with geofabrics; pore-pressure reduction |
| B5 | Civil, Hydraulic and Geotechnical Applications on Vertisols | Design for cracking clays, where behavior differs sharply from other soils |
| B6 | Standard Specification for Slope Stabilization Using Vetiver Grass | Book by Dr. Mohammad Shariful Islam |
C — Wastewater, effluent and pollution control
| Code | Module | What it addresses |
| C1 | Constructed Vetiver Wetlands for Coffee Processing Effluent | High-organic wastewater; reduces BOD and COD; neutralizes acidity |
| C2 | Raw Sewage Treatment | Pathogen and nutrient reduction; improves discharge quality |
| C3 | Tertiary Treatment of Residential and Industrial Wastewater | Polishing to compliance standards; removes residual solids |
| C4 | Oil Palm Mill Effluent (POME) Treatment | Extreme organic load; oil removal; clarity |
| C5 | Landfill Effluent (Leachate) Treatment | Toxic leachate; heavy-metal uptake; ammonia reduction |
| C6 | Vetiver Rain Garden Design and Implementation Manual | Urban and plot-scale stormwater management |
| C7 | Guide and Specification for Constructed Vetiver Wetlands, Coffee Effluent | Contract-ready specification companion to C1 |
D — Livelihoods, products and community systems
| Code | Module | What it addresses |
| D1 | Handicrafts | Vetiver-based craft production; rural enterprise; income for women’s groups |
| D2 | Integrated Vetiver Oil and Slip Production | Oil plus planting material; value chains; supply reliability |
| D3 | Farm Soil and Water Conservation, with by-products and co-benefits | Conservation plus fodder, mulch, craft material and fuel |
| D4 | Microbial Root Dips for Vetiver Establishment (v3) (new) | Farm-made inoculant to improve establishment and root regeneration |
| D5 | Vetiver and Arbuscular Mycorrhizal Fungi — soil health, water and nutrient transfer (v3) (new) | Shared mycorrhizal root zone between hedge and crop |
| D6 | Nematode Suppression and Soil Biological Recovery (v3) (new) | Vetiver as a dead-end trap for nematodes in fields and agroforestry |
| D7 | Dead-End Trap Plant for Cereal Stem Borers (v3) (new) | Stem borer management in maize, sorghum and rice; hedge design; parasitoid support |
| D8 | Forage Management of Vetiver Grass (v2) (new) | Cutting regimes for forage yield, quality and drought reserve |
| D9 | Kitchen Garden, Vetiver Based | With fact sheets D9a English and D9b Swahili |
| D10 | Chrysopogon nigritanus (African black vetiver) compared with C. zizanioides (Asian vetiver) | Species choice; D10a adds Napier (Pennisetum purpureum) as a third comparison |
| D11 | Vetiver Floating Islands and Tilapia Farming | Combined water quality and aquaculture production |
| D12 | Agriculture, Soil Health and Water Management on Vertisols | Farm-scale companion to B5 |
| D13 | Vetiver Farm Model Package | Six model applications with start guides, fact sheets and support files |
| D14 | Vetiver and Soil Carbon (v2) (new) | What can and cannot be claimed for soil carbon accumulation under vetiver |
Keeping the package current
These standards will keep developing, because VGT is a living technology and innovation, field learning and practitioner experience remain essential to it. TVNI welcomes feedback, case studies, corrections and technical contributions. Where errors are identified, modules are revised and the package is reissued; new modules are added as they are completed. Contradicting field evidence is as welcome as corroborating evidence, and more useful.
| Disclaimer. These standards are provided as guidance only. TVNI does not assume responsibility for project outcomes. The performance and results of any vetiver application depend on the decisions, designs, supervision, and workmanship of those who plan, specify, and implement the work. |