NEWSLETTER (NL2026-06): Attention: wine industry, Vetiver’s shifting climatic range, Hedging Bets: Sequestration vs. Storage Reality

On hikes that passed through wine-producing regions in Europe, scenes like those pictured below prompted thinking about how the Vetiver System could benefit vineyard owners around the world.

Wine grapes want slopes – for drainage, for sun, for the cool air that drains off a hillside at night – and slopes lose soil. In Europe, vineyards are among the most erosion-prone farmland, and it is likely little different in the other wine grape growing regions of the world, including the new high-latitude and tropical-highland regions. In these latter, cool high-latitude regions growers chase steep, sun-facing slopes to ripen the fruit, while in the hot low-latitude regions they climb to altitude to cool it down – and both end up on the same steep, erosion-prone ground.

In talking with a vineyard owners and managers it was clear that they have been seeing, feeling, and adapting to climate change impacts for decades now.  Long grape-harvest records in Europe show that impacts have been measurable for about four decades already. In Burgundy, a 664-year series of harvest dates breaks sharply around 1987–88, with grapes picked about 13 days earlier on average than in the prior six centuries! Across France and Switzerland, harvests now run about 10 days earlier since 1981, and that recent shift is driven by warming even in years without drought. And, while climate change is threatening wine production in its traditional heartlands (like Bordeaux in France and inland Australia), it is widening the wine grape production map poleward, to above ~50°N. Across England and Wales – and, newer still, Norway, Sweden, Belgium, Denmark, the Netherlands, Poland, the Baltic states, and Nova Scotia – the warming climate and longer growing seasons are driving the poleward expansion, ranging from the UK’s now-established sparkling-wine industry to a fast-growing pioneering fringe built largely on cold-hardy hybrids.

In subsequent articles in this newsletter we will explore what VS might contribute to climate adaptation for vineyard managers, including the question of where the Vetiver System (VS) might fit into vineyard management around the world, and where it does not. As a corollary to the story about wine production areas expanding poleward in function of changing climate, we will also explore the question of the extent to which VS’s usable range is also moving north across North America and Europe, south into the cooler margins of South America, southern Africa, and Australia, and to higher elevations in the tropics and subtropics as warming winters and rising frostlines open terrain where a generation ago vetiver perhaps only survived but now could be effective.

Attention wine industry: Vetiver as an option for building resilience and mitigating climate change impacts in vineyards

Vetiver has a long, well-documented record in perennial and tree crops, but what we know about its use in grape vineyards comes from only a handful of reports from network members, summarized below. As best can be determined, we have no published trials of vetiver hedgerows in a working vineyard to draw from.

• In Tuscany, growers in the Massa Carrara hills used the Vetiver System after the 2010 landslides to stabilize vineyard terraces against slippage and erosion, reporting an 11% increase in grape weight (juciness); secondary gains in soil moisture, organic matter, mulch from the cut leaves; and a 50% reduction in pesticide and fungicide applications; and, with vetiver mulch lasting 70 to 90 days, a reduction in weeding intervals to once in 20 to 25 days vs once every 10 days as before.
• In Vietnam, the Vetiver Farmers Group observed grapes — along with papaya and dragon fruit — growing with unusual vigour beside vetiver hedges, an effect attributed to vetiver’s suppression of the root-knot nematodes to which all three are highly susceptible.
• In China, the Yunnan Vetiver Network recorded having interplanted vetiver with fruits, including grape vineyards in Baixian County of Chuxiang, and achieving soil and water retention improvement, insect protection and income increases.
• In New Zealand, it was reported that in a small Syrah grape orchard, that the grape vines associated with a 10 year old vetiver planting, which

  

  was initially installed for slope stabilization, appeared to out yield the other vineyards in the area, and have less trouble with pests and diseases.

• In Spain, an Andalusian supplier reports supplying vetiver to vineyards across the EU.
• In Madagascar, rings of vetiver were planted around grape vines, and the grower saw more than a doubling of production

While these reports provide a scattering of reported experiences, they point consistently in the same direction. And, while the reported production gains and impacts should be read as observations awaiting empirical confirmation, as a body of practitioner experience they are enough to merit attention.

Combining those few experiences with what we reliably know vetiver does in comparable settings, several distinct options for the wine industry (and table grape industry) to build vineyards’ resilience, reduce vulnerabilities, sustain long-term production, and adapt to a changing climate seem clear.

• Holding the land base together. The first and best-supported function is structural: a contour hedge slows and spreads runoff, traps the sediment it carries, and over time anchors the very ground the vines grow on. In terraced and steep-slope vineyards this means stabilizing risers, armoring drainage lines, and arresting the slumps and blowouts that intense storms trigger. As rainfall arrives in fewer, heavier downpours, this converts a destructive event into infiltrated water and retained soil, protecting the irreplaceable topsoil that underwrites production and keeping the physical vineyard intact through the kind of weather that is becoming more frequent.
• Capturing and banking water. The same slowing of runoff means more rain enters and is held in the soil profile rather than leaving the block, recharging the root zone ahead of dry spells. This is the mechanism behind vetiver’s documented moisture conservation around tree crops, and behind the Vietnamese growers’ observation of healthier vines nearby. In an era of longer droughts and erratic rainfall, banking more of each rain event in the soil is a direct buffer against water stress.
• Building and cooling the soil. Trimmings laid down as mulch add organic matter, shade the surface, cut evaporative loss, moderate the soil-temperature extremes that heat waves bring, and keep topsoil and its biology in place. These allow vineyard soils to buffer stress. With researchers now linking rising soil temperatures to vine decline, a cooler, better-covered, more organically rich soil is a quiet but real source of resilience.
• Easing below-ground pest pressure. Grapevines are notably vulnerable to root-knot and dagger nematodes (the latter a vector of fanleaf virus), and this pressure worsens as soils warm and resistance genes falter. Vetiver’s documented nematode-suppressing effect in the root zone – the most plausible explanation for the Vietnamese observations – points to a genuinely valuable role, reducing a chronic and climate-aggravated stressor. This is also the function most in need of vineyard-specific testing before it is relied upon.
• Hosting beneficial life. A permanent hedge provides habitat for parasitoid wasps, predators and pollinators, aligning with what the vineyard cover-crop literature already shows about ground cover and biodiversity, and how adding layers of biological buffering to otherwise monocultural slopes provides real benefits.
• Protecting infrastructure and operations. Beyond the vine rows, vetiver stabilizes access-road cuts, drainage lines, headlands and terrace ends, all needed to keeping a vineyard working. And, where stone walls and engineered earth banks fail catastrophically (as seen in Photo 1), as living infrastructure the vetiver self-repairs, rises with accumulating sediment and lowers per-event maintenance costs, providing a needed adaptation tool as extreme events grow more common.

For Europe, Eurac Research’s Winemap (Photo 3) rates European PDO region’s climate-change vulnerability as a function of its exposure (projected warming and declining rainfall), its sensitivity (the narrow climatic range of its traditional varieties), and its adaptive capacity (its financial, natural, physical, social, and human resources for coping). Based on the IPCC framework, it shows the highest-risk regions clustered in Southern and Eastern Europe. In these regions, vetiver can strengthen adaptive capacity by conserving soil, banking soil moisture, and supporting soil health and biodiversity, and by stabilizing terraces, drains, roads, and other vineyard infrastructure. Vetiver can buffer the field-level consequences of exposure to climate change impacts, blunting the erosion of heavier downpours and the moisture loss of longer dry spells.

Where and when vetiver may not be the right tool in vineyards

 There are several common vineyard situations where vetiver may not fit. In some conditions it might be redundant, and in others be at odds with established good practices.

• Flat/low slope, fully mechanized blocks. The vineyard’s standard floor-management tool is already a good one: the inter-row cover crop, a sown or volunteer vegetative cover (grass, mustard, etc.) in the alley that is cheap, flexible and, above all, compatible with machinery, since it can be mown, rolled, tilled in or terminated on schedule. In flat or gently rolling, fully mechanized vineyards, a permanent vetiver hedge planted across the rows would be an obstacle, not an asset. Vetiver is not a replacement for the inter-row cover crop; it is a complement that belongs on the structural features the cover crop and the tractor cannot hold — terrace risers, drainage lines, road cuts and steep breaks.
• Where the vine is deliberately water-stressed. This case needs the most careful thought in dry-farmed vineyards, where growers stress the vine on purpose for quality. The question here is the net balance in a dry spell. The evidence is reassuring but incomplete. Research in California found no competition between vetiver and either shallow- or deep-rooted crops under irrigation or average rainfall; only in drought years, and only on heavy vertisol soils, did a hedge measurably reduce an annual crop’s moisture and yield, and then only within about 5 ft (1.5 m) of the hedge line. More tellingly for perennial vineyards, vetiver planted in rows, semicircles, or individual clumps directly around fruit and tree crops in low-rainfall regions has improved yield as a water-harvesting technique — lychee in Thailand by as much as 20% — with cut-leaf mulch further cutting evaporation. The balance, in other words, can be made positive, but it is configuration- and site-specific layouts remain to be tested in grapevines under deliberate stress.
• Where the rows run with the slope. On steep, un-terraced slopes, rows are often oriented straight up and down for machinery access and operator safety, which is also the orientation that channels flows and creates erosion problems (e.g., in wheel tracks). A cross-slope vetiver hedge is the hydrologically correct answer but would conflict with that traffic pattern. Under these conditions the grower must weigh which matters more, or confine vetiver to the headlands, the upper break and the natural drainage lines rather than the rows themselves.
• At the cold margins. Vetiver is a tropical grass with nonetheless remarkable cold tolerance once established. However, at the cool, high-latitude edge of the expanding wine map, cold hardy grape cultivars go dormant and will survive harder freezes than vetiver. So at the cold edge of these newly opening regions, vetiver’ may be past its limits.
• Regulatory constraints. Some appellations and certification schemes regulate inter-row management and permitted species, and in protected landscapes there may be restrictions on introducing a non-native grass.

Vetiver’s Shifting Climatic Range

Some thoughts on how a warming climate is widening where the Vetiver System can be used – and how to tell whether your area now qualifies.

Why the range is changing

Watching vineyards push into country that was too cold for wine a generation ago – into England, Belgium, and southern Scandinavia – raises an obvious question for our own work: if the wine map is shifting, is vetiver’s? The short answer is that the ground where the Vetiver System can be put to work is widening in three directions at once.

What sets the edge

Vetiver’s range has two limits. The first is winter cold or, in the tropics, altitude, which decides whether the plant survives: frost kills the leaves, but the growing points sit at and just below the soil surface, so the crown regrows after hard frost and gives out only when the soil freezes deeply, around −15 °C (5 °F) at depth. That puts the reliable cool edge in the USA to be near USDA Zone 8a.

The second limit is growing-season heat and sunshine, which decides whether vetiver establishes into a working hedge. As a full-sun C4 grass it grows best near 25° C and barely at all below about 15° C, so a mild but cool, cloudy, maritime site can sit comfortably inside the hardiness zone and still be too dim and too cool for an effective hedge to form within a practically useful period. Survival and performance are not the same thing, which is a point that matters most precisely where the range is now expanding.

Three directions of expansion

• Poleward, across the U.S. mid-South, the maritime Pacific Northwest, and parts of western and central Europe. The 2023 USDA hardiness map averages about 2.5 °F (1.4 °C) warmer than its 2012 edition, with roughly half the contiguous U.S. shifting a half-zone warmer – the same poleward creep now carrying cool-climate viticulture north.
• Upslope, in the tropics and subtropics, as frost lines lift a few hundred feet, the cold ceiling on montane planting rises with them.
• Into the cooler temperate margins of the southern hemisphere – southward through southern Brazil, central Argentina and Chile, southern Africa, and southern Australia – where the same warming relaxes the winter limit.

Two thresholds set the range, and both are read most reliably from climate data. Survival turns on winter cold or, in the tropics, altitude. Vetiver’s crown is killed when the soil freezes to about −15 °C (5 °F), which puts the reliable cool edge near USDA’s Zone 8a in the USA. Vigor turns on the growing season: a full-sun C4 grass grows best near/above 25°C and barely below about 15°C, so a stand grows fast almost anywhere warm – the hot, humid, often cloudy tropics included – and slows only in genuinely cool-summer maritime climates (coastal fog belts, cool oceanic margins), where it may take years to closeup into a hedge. The Köppen-Geiger climate classes capture both axes at once, which is why they map vetiver’s range better than latitude or hardiness zone alone.

How far, and how sure

By mid-century the band widens again: many temperate regions are projected to warm roughly another 2°C by 2050, lifting both the poleward and the upslope edges. That shift can now be read straight off the Köppen-Geiger projections, whose 1-km maps run to a mid-century window (2041–2070) and beyond – comparing a site’s present class with its projected one shows whether, and roughly when, it crosses into a more favorable band. But this is a frontier, not a finished map. At the cold and cool-maritime margins survival is real but closure into a functional hedge can take two or three seasons, or never fully happen on a cool, foggy coast. The working rule for the expanding edge is simple: verify locally, and trial before committing vetiver to any critical, no-fail application.

Is your area newly in play?

In discussions with John Greenfield into the late 1990s, his rule of thumb put vetiver’s general reliable limit near 30° latitude (north and south), pushed further only where coastal/maritime mildness or a Mediterranean climate tempered the winters. These are the same limits found in his technical guide, which records vetiver “grown successfully as far north as 42° latitude,” and nurseries in southern Portugal and Murcia, Spain operated near 37°N. So, the late-1990s picture was: ~30° as the broad limit, with mild coasts and Mediterranean climates as the exceptions that reached toward ~42°.

Warming has since moved that survival edge. Table 1. locates the main expansion fronts – then, now, and toward mid-century.

The cross-cutting message: two questions, not one. “Will it survive?” (winter cold and altitude – now relaxed, so more area qualifies) and “will it form a working hedge?” (summer heat and sun – little changed in maritime zones). Warming has widened the first far more than the second. So the newly opened ground splits into genuinely usable warm-continental and montane sites, and mild-but-cool-cloudy maritime sites where vetiver now survives but still may not reliably close. Table 2. attempts to tell which you are in and whether you need to trial/verify before any attempting any “no-fail” use.3. Self-check: Köppen climate → risk tier

Find your site’s Köppen-Geiger class on a 1-km map (use the exact location, not the regional average), then read across to its risk tier, an extrapolated/theoretical likely time-to-closure, and the factor that would be most limiting. To see whether the site is newly in play, compare its present class (1991–2020) with the projected mid-century class (2041–2070): the Beck et al. (2023) maps at gloh2o.org/koppen carry both, across a range of emissions scenarios.

What the tiers mean

• Tier 0 – No risk. Closes ~1 season; robust throughout. Any use, including critical “no-fail.”
• Tier 1 – Minor risk until established. Vulnerable only in the establishment window; manage timing/water. OK for critical use with that management.
• Tier 2 – Minor risk when established. Closes acceptably with a low ongoing vulnerability. Most uses with monitoring; add redundancy for critical work.
• Tier 3 – Moderate risk. Slow or incomplete closure. Not for critical “no-fail” work; supplemental only, or after a site trial.
• Tier 4 – High risk / unsuitable. Will not reliably survive or close. Choose another method.

 

The two thresholds

1. Winter cold / altitude (survival). Is the site about USDA Zone 8a or warmer – i.e. does the soil avoid freezing below roughly −15 °C (5 °F)? If so, the crown overwinters. This is the factor that climate change-related warming is relaxing.
2. Growing-season warmth and sun (vigor). Are summers genuinely warm (monthly means well into the warm range) and the site sunny rather than deeply shaded? Vetiver grows fast almost anywhere warm; the only climates that fail this check are the cool-summer maritime ones – cool, cloudy oceanic and fog-belt zones – where it survives but is slow to close (Tier 3).

Roots grow above about 13°C and best near 25°C, with little shoot growth below about 15°C; as a full-sun C4 grass vetiver is shade-intolerant. Those numbers are what the Köppen tiers indicate.

Cautions

• Köppen codes smooths over microclimate – fog and insolation, frost pockets, slope aspect, continentality. One code can span two tiers: the SF Bay Area runs Tier 1 (hot inland East Bay) to Tier 3 (SF fog belt) under essentially one code. Always finish with a local check.
• Closure times are theoretical estimates based on climate; but they also heavily dependent on planting material quality, planting density (spacing), soil, water, and management.
• Tiers are predictions of performance. Initial trials should be carried out in any new cold, high-altitude, or cool-maritime margin before utilization for a critical application.
• NOTE: A number of sources (for example) have attributed observed differences in cold survival to the different vetiver “cultivars” used, i.e., to genetic differences. That there are significant genetic differences  among the different accessions these sources report was not established by the authors.  As found by Bob Adams virtually all the vetiver used for erosion control outside South Asia derives from a single genotype that represents a single sterile clone. He named this the “Sunshine” genotype, and it includes Monto, Vallonia, Huffman, Capitol and the other non-fertile accessions with very similar profiles. He referred to this as the “Sunshine genetic cluster”. Therefore, it is as much or more likely that observed differences in cold tolerance of vetivers within the Sunshine cluster were the result of “cold acclimation (hardening), age, and establishment rather than genotype.

Hedging Your Bets: Sequestration Claims vs. the Storage Reality

Over the past several weeks, TVNI has reviewed a cluster of vetiver carbon studies published between 2024 and 2026: Tessema et al. (2024) on soil carbon fractions in Australia and Ethiopia, Resqiyanto et al. (2025) on slope-reinforcement bioengineering, Parameswari et al. (2025) on effluent-contaminated soils, Lavania et al. (2024) on designer genotypes, Singhal et al. (2025) on aggregate-level carbon stabilization across restoration grasses, and Hailu et al. (2026) on a four-year Ethiopian hedgerow trial.

The review turned up a familiar problem that has not gone away with newer publications. Researchers continue to conflate biomass production and temporary carbon storage with genuine carbon sequestration – treating standing biomass, gross photosynthetic flux, or a single point-in-time soil sample as if it were proof of durable, decades-long carbon removal. This is not just an academic argument that is confined to journal pages. It feeds directly into the public claims made by vetiver proponents, including TVNI itself. Until recently our own carbon sequestration page stated that “a number of research papers suggest that vetiver may create 20-30 tons SOC/ha/year” – a figure that, left unqualified, is simply not credible, and repeating it without context risks undermining the credibility we are trying to build for vetiver as a serious climate tool.

It is worth being precise about why that figure is implausible. Dr. Rattan Lal – World Food Prize laureate and Director of the Rattan Lal Carbon Management and Sequestration Center at Ohio State University – has set out benchmarks that TVNI will treat as authoritative until such time as science giver as better information for vetiver. According to Dr. Lal’s many decades of research and work in this subject, tropical grasses, vetiver included, can realistically be expected to accumulate stable soil organic carbon at a rate on the order of 1 metric ton SOC/ha/year. A claim of 20–30 tons/ha/year is not a generous estimate within a wide range; it is roughly twenty to thirty times Dr. Lal’s own benchmark, and it does not hold up against the carbon physics he describes – namely, that only a modest, mineral-protected fraction of plant-derived carbon ever stabilizes in soil over decadal timescales. Most of the inflated numbers circulating in the literature, and consequently in advocacy materials, come from exactly the conflations described above: gross biomass or photosynthesis presented as sequestration.

None of this means the underlying biomass is irrelevant – it means it has been pointed at the wrong question. As we noted in TVNI’s July 2024 Newsletter (NL-2024-07), the European Union’s carbon removal certification framework now formally recognizes temporary carbon storage from carbon farming as a legitimate, certifiable activity in its own right – separate from, and with a materially lower evidentiary bar than, permanent soil sequestration. A hedge does not need to prove decades of stable humus formation to qualify here; it needs a defensible, monitorable carbon stock.

That reframing is what makes this body of literature useful after all. The same biomass, root-ratio, and decomposition data that cannot support sequestration claims are exactly the data needed to estimate a reasonable magnitude for temporary storage in a managed vetiver hedgerow – above- and below-ground carbon held in living tissue for as long as the hedge stands. The remainder of this article attempts to set out what that more modest, better-supported estimate might look like.

Two Different Questions, Often Confused. Carbon scientists draw a sharp line between carbon sequestration – carbon locked into stable soil organic matter over decades – and carbon storage – carbon held in living biomass for as long as that biomass exists. A lot of published vetiver research blurs this line, treating standing biomass as if it is a proof of long-term sequestration. They’re not the same claim, and they don’t need the same evidence.

The good news: storage is the easier case to make, and it’s one the EU now formally recognizes. Its new carbon farming rules (still being finalized through 2026) explicitly allow temporary biomass storage as a certifiable climate benefit in its own right – no decades-long soil stability required, just a defensible, monitored stock.

So: what does that stock look like for a real, working hedge?

 A Hedge Will Build Up Carbon in Stages. Picture a single row of vetiver, cut back to 50 cm every year to stay healthy and to keep the household or farm supplied with mulch. Two things happen simultaneously after planting:

• The standing crown and stubble – what’s left after each cut – thickens up over the first few years. And the root system, vetiver’s real signature feature, pushes down and densifies, eventually anchoring a deep, fibrous mass that can extend several meters into the soil.
• Both pools grow fastest in the early years and then level off as the hedge matures and settles into a stable annual rhythm of cutting and regrowth. Pulling together the best field data currently available – a multi-year Ethiopian field trial under real cutting management, an age-tracked Thailand trial showing production still climbing at two years rather than leveling off, and independent root-density measurements from Australia and the US – a mature, well-established hedge probably plateaus at roughly 0.5–1.5 kg of stored carbon per linear meter, the majority of it below ground. Three independently measured root-carbon figures land in the same general range, which gives more confidence than any single study would on its own.

Translated to a farm scale: a hedge network spaced at 10 meters apart across a hillside might hold somewhere in the order of 0.7 tons of carbon per hectare once mature – not a flux, but a one-time stock built up over the establishment years and then maintained as long as the hedge stands.

A note on bigger numbers you may have seen elsewhere: some sources, including TVNI’s own materials, cite figures well above this – in the tens of tons per hectare per year. Those are almost always measuring something different: total biomass produced or cycled through the system, not durable storage. It’s the same distinction this article makes at the outset and it’s worth applying consistently, including to our own published numbers.

Inside the Model: the Numbers and the Assumptions Behind Them. For readers who want to see the working, not just the headline figure, here’s the model laid out directly – what it assumes, what it produces, and where each piece comes from.

What’s counted, and what isn’t. The model tracks two carbon pools inside the hedge itself: the standing crown and stubble left after each annual cut, and the root system. It deliberately excludes the cut material itself – the mulch that’s removed each year and applied elsewhere. That mulch carbon is real, but once it leaves the hedge it’s a separate, faster-turnover story playing out on whatever field receives it, not part of what the hedge itself is storing.

The starting assumptions:

• A single hedge row, roughly 0.5 metres wide at maturity.
• Cut back to 50 cm once a year, with the cut material removed as mulch rather than left in place.
• Both the permanent crown/stubble and the full root system count toward the stored stock; the annual mulch harvest does not.
• The hedge follows a standard establishment curve for a perennial grass under repeated cutting: fast early growth, then a tapering approach to a stable mature size, rather than an instant jump to full size.

 

The trajectory. Per linear metre of mature hedge, here’s how the stock builds and how the annual increment changes as the hedge matures (mid-range estimate). Remember, to convert C to CO2,multiply C by 3.67

Notice the shape: the increment actually grows for the first three years as the root system gathers pace, then falls off quickly as the hedge approaches its mature size. By year 5, the hedge holds roughly 94% of its eventual total; by year 7, effectively all of it.

The magnitude, and how confident can we be in it.  Because real-world conditions vary enormously – soil, water, climate, how well a hedge is maintained – the model carries three scenarios rather than one number:

The mid-range figure is anchored on a multi-year Ethiopian field trial under real cutting management, and then checked against three independent root-carbon measurements – from Australia, Thailand, and the southeastern US – that all land in roughly the same range. That kind of agreement across unrelated studies, methods, and continents is a meaningfully stronger basis than any single number on its own, even though none of them measured a hedge exactly like the one this model describes.

What this model is, and isn’t. It’s a synthesis built from the best available proxy data, not a direct measurement of one hedge tracked from planting to maturity – because that study doesn’t exist yet (more on that below). Treat the shape of the curve as a well-supported expectation, and the specific numbers as a starting point for discussion that will sharpen as more field data comes in.

How Fast Does That Happen?  Here’s the honest caveat: the timeline is an estimate, not a measurement. The best-supported pattern, based on how vetiver’s root system is known to develop – pushing down to several metres over multiple growing seasons rather than reaching maturity in one – points to roughly 5 to 7 years before a hedge reaches its full storage potential. But no single study has tracked one hedge, under one consistent management regime, long enough from planting to plateau to confirm that timeline directly.

That’s the single biggest piece of missing evidence in this picture – and a strong candidate for some researcher or interested organization to help fill with field monitoring.

What This Means Going Forward.  The EU’s temporary carbon storage framework isn’t operational yet for agricultural land – the specific methodology is still being finalized, expected later in 2026. But the direction of travel is clear, and a managed vetiver hedge is a genuinely plausible fit for it: a real, monitorable, defensible carbon stock with a known establishment curve, built on a practice already valued for erosion control and soil and water conservation.

The numbers above are a starting estimate for discussion, not a certified figure – and they’ll get sharper as more field data comes in. If your project has multi-year biomass measurements from a managed hedge, it would directly help close one of the more important open questions in this space.