I was first introduced to vetiver grass on the island of Grenada.
There, it was called “sweetroot grass,” and my friend James “Mike” Thomas told me about how farmers used to plant it everywhere along roads and hillsides to stop erosion. He also told me it was no longer common, but there was still some here and there.
Some time later, I visited a farm where it was being used. Once I recognized the clumps of grass on their hillside, I asked the owner about them. She had turned them into a regular business, selling vetiver starts to farmers and gardeners, so I was able to buy some from her to install on our own little piece of land.
Then we moved, and those experiments came to an end.
Until I got some vetiver again about two years ago, and planted some at the end of one of my Grocery Row Gardens so I could start a patch we could propagate from.
Here it is today:
That clump of vetiver grass is about 8′ tall. I pulled it up once and divided off a bunch of vetiver starts, then replanted it, so who knows how big around it might be if I’d left it alone!
Vetiver is known as a tropical grass and I couldn’t find any information on its cold-hardiness.
The only answer was to plant it and see!
Now I can safely recommend it to gardeners in zone 8b. It’s survived two winters thus far – one of which had an overnight low of 16 degrees, and the next winter, which had an overnight low of 17 degrees. That’s quite cold for a tropical grass, yet it survived and sprang back thick and green in the spring.
Today, while researching vetiver again, I read that:
The plant has a wide range of adaption and will tolerate soil pH from 3 to 11, temperatures from -15 to +55 degrees C and is extremely drought proof, and yet can survive complete submergence in water for at least 3 months.
That is a minimum temperature of 5 degrees, which means vetiver should survive through all of zone 8 and up into zone 7.
We propagated it for our nursery in the spring and sold some pots of it, but it was less popular this spring than we thought it would be.
I think once people understand its usefulness, they’ll want it. It can stabilize hillsides and stop erosion, feed animals, be used for the essential oil in its roots, be turned into baskets, be used as a chop-and-drop – and as Vetiver.org reports:
“Studies indicate that there is a significant increase in infiltration due to large, dense and deep roots, and large soil pores with respect to SGH grasses, Dabney (1996). This increased infiltration results in reduced runoff. A study by Rachman (2004) indicated that hydraulic conductivity within the hedgerow (130 mm h1) was 7 times more than in comparative row crops maize (18 mm h1), and 24 times more than in the fully saturated adjacent sediment deposition area (5.4 mm h1) immediately upslope of the hedge”. In effect a vetiver hedge acts as a very safe vertical drain, directing part of the flow for groundwater recharge, and the balance spread evenly through the hedge to downslope land. “
That is a good grass. We need to plant more. It’s non-invasive and it’s a multi-tool!