A different style of grass is growing on people in Costa Rica.
Vetiver (Chrysopogan zizanioides), a grass native to India and known for its erosion prevention qualities, is taking root in private developments and public works projects throughout the country to help weather the strongest part of the rainy season.
The plant commonly has been used in other Latin American countries to guard against landslides and flooding, and its extremely high success rate has led many to consider it a virtual “miracle grass.”
“It’s an insane grass,” said Steve Gordy ofGreengoGardensin Guanacaste. “It holds everything together and it grows in anything. It’s just nuts.”
The secret to vetiver’s strength is what lies beneath the soil. Unlike most grasses, its roots grow straight down into the ground instead of spreading horizontally. The grass grows in clumps and its roots usually reach a depth of three meters. This makes it ideal for holding soil in place and blocking the runoff of surface water.
Because the leaves do not release any seeds, vetiver is easy to control, according to Gabriela Soto of the Tropical Agronomy Research Center (CATIE). Some exotic grasses can spread rapidly and become an ecological menace, displacing native plants and trees.
But Gordy said that with a little digging and a few tugs on the root, the grass will be removed and will not grow back until replanted.
The grass has been popular in other countries around the world but has been slow to sprout in Costa Rica.
Juan Bonilla, an engineer for the Highway Beautification and Security Association (ASECAN), blamed the grass’s tardy acceptance in Costa Rica on cultural reasons.
“It’s a lack of education,” he said. “It hasn’t been used much here because people aren’t aware of its benefits.”
ASECAN, a branch of the Ministry of Public Works and Transportation (MOPT), has recently planted experimental plots of vetiver along highways throughout the country, and it is proving successful in holding back landslides.
The public works group is planting 3,200 more plants in Socorro, a neighborhood in Santo Domingo, north of San José, where a landslide buried a car and killed two people last year. This project was expected to be completed as of today, June 12.
“This stuff works really well, and I think once people see the results, they will start to use it more,” Bonilla said.
While vetiver has proven extremely useful in warm climates, its effectiveness in colder areas has not been tested extensively.
One of the reasons for the roadside plot in Socorro, where the temperature is cooler, is to determine the feasibility of completing a large scale project in Cinchona, an area with a similar climate and a zone ravaged by the January 8 earthquake.
Bonilla doesn’t anticipate any problems in Socorro, and he hopes to start a project in Cinchona before September and October, the rainiest months.
While vetiver is just starting to sprout in the Central Valley, developers outside of San José are not surprised by public officials’ new obsession.
Doug Stern, a managing partner at Tierra Pacifica in Guanacaste, has used the “miracle grass” at his development for five years. When he arrived at the northwestern province, roads flooded often and were blocked with mud.
After planting thousands of linear meters in 2004 along roadways and riverbanks, Stern has not seen any flash flooding or erosion.
“It really is an amazing grass,” he said. “It’s a shame it took so long to discover it. I think we are all going to look back and realize how stupid we were for not having used it all the time.”
