Not Every Vetiver Job Needs a Hedge

A new quick-reference sheet on choosing the right layout — and a request for corrections

A farmer has a patch of low, wet ground where only rice will grow. He plants a contour hedge across it, because a hedge is what vetiver looks like. Not much happens.

There was no runoff for the hedge to intercept. The problem was a water table sitting just below the surface, and what that ground needed was vetiver planted in a block, to open the profile and let the water drain away.

That mistake, and its opposite, are the commonest failures in vetiver work. Not bad planting. Bad layout. The opposite case is scattered clumps where a continuous line was needed: the runoff finds the gaps between them, and the gullies keep growing.

One question decides it

Hedge or Stand-alone? is a new quick-reference sheet for choosing the layout. It turns on a single question: what is the vetiver being asked to work on?

• Moving water. A hedge, planted on the contour.
• Standing water, or a water table. Blocks, or scattered clumps.
• The soil itself — its permeability, rooting depth, biology or temperature. Blocks, clumps, or single plants set between trees in an existing row.

Twenty-two situations are listed against the layout each one needs, the reason it needs it, and which GVF farm model covers it.

For farms, the models already have the answer

Nobody should be building a farm layout out of a table. V101, V101-E, V48, VCR, VFF, VPGS and the Kitchen Garden each arrive as a package: layout, plant density, spacing and cost. For a farm, the sheet’s job is to point you at the right model and then get out of the way.

The models also settle something the sheet cannot: how much to plant. Hydraulics sets the minimum. Everything above that minimum — mulch, cooler soil, mycorrhizal reach, nematode suppression, fodder — you buy by planting more, and the ladder is already costed. V101 yields 2 to 4 tons of mulch a year, with mycorrhizal benefit only in the hedge zone. V48 yields 8 to 18 tons, benefit across the whole field, and one to three degrees of cooling. VCR reaches 28 to 43 tons. Only V101 and V48 are fully validated. The rest are projections, and an early adopter is a collaborator rather than a customer.

The sheet earns its place on the work the models leave out: retrofitting twelve kinds of existing structure, road and drainage works, spillways, canal banks and dams. It also sets out what each layout demands of you, the two numbers people always ask about, and the six mistakes that keep recurring.

It is no longer one page

It started as one page and is now six. That happened because practitioners kept correcting it. Vetiver belongs at the toe of a bund, not spread over the body of it like turf. An off-contour hedge can usually be repaired with short spur hedges rather than replanted. A retrofitted bund gains capacity over time, as the hedge builds its own terrace in front of it. An earth spillway wants vetiver planted across the flow, not beside it. Every one of those came from someone who had done the work.

The sheet is the fastest route to an answer, not the whole of it. Where it gives a figure or a limit, the reasoning and the evidence behind it sit in Vetiver Hedge Mechanisms and the Vetiver and Water note. The sheet tells you what to plant and where to put it. The standards tell you why, how far to trust it, and what nobody has measured yet.

And a request