Good riddance: BIISC announces its success in eliminating pampas grass

Good riddance: BIISC announces its success in eliminating pampas grass

The Big Island Invasive Species Commission announced last week that invasive pampas grass has been eliminated from the Big Island.

There are two types of pampas grass in Hawaii: Gopata snapped And Cortaderia is crying; Both are listed on the state’s noxious weed list. Both have been removed from all known locations on the island of Hawaii.

Pampas grass was popular in the 19th century, and has spread widely and been planted across the Pacific, growing to become a major problem in places from California to New Zealand. It is now widespread on Maui, and because it is adapted to fires in its native habitat, it poses a major threat in Hawaii as a wildfire fuel.

When eradication efforts began on Hawaii Island in 2007, the plant was mapped at more than two dozen sites. Plant removal by Big Island Invasive Species Commission (BIISC) crews took time, as permission from property owners was required for most sites. Locating and contacting property owners can be a significant challenge to control efforts, but overall most homeowners have been cooperative and eager to support the removal of the invasive plant from their property. The state Department of Agriculture helped secure access for the removal where permission was difficult to obtain.

When BIISC crews removed the last known plant in 2019, they replanted the area with native mamaki trees. Although most adult plants are removed early in the eradication schedule, with seeds potentially spreading up to 20 miles, scanning for pampas grass near known sites requires a significant investment, said Joel Brunger, BIISC’s field operations supervisor. For time. .

“After we remove the adult plants, we have to go back and do regular sweeps looking for new keiki as long as the seeds are viable,” Pronger said. “For pampas grass, that’s six years.”

Despite the sharp leaves, pampas grass is still sold worldwide in the horticultural and landscape trade. During the eradication effort, BIISC developed the Plant Pono Program, a nursery education and advocacy effort aimed at stopping the sale of invasive plants in Hawaii. Certified Plant Pono nurseries voluntarily pledge to sell only non-invasive “pono” plants. There have been no sales of pampas grass in Hawaii for the past several years, although seeds purchased online still pose a risk of introducing invasive plants.

“People often look at widespread invasive plants like Albizia or Cledemia and wonder, why didn’t anyone do something about it before it got this bad?” says Frannie Brewer, communications director at BIISC. “That’s what we’re trying to do. Identify what’s happened that could potentially be the next serious problem, and eliminate it before it spreads for decades.”

Once harmful species reach a certain point, complete eradication becomes so expensive — in the tens or even hundreds of millions of dollars — that removing the species is no longer possible, she added.

Currently, BIISC is targeting a number of other plants for eradication, including the Mollucca mulberry, a sprawling, thorny species and holly tree that can establish itself in native forest areas. As with pampas grass, public reporting is a critical tool in efforts to eradicate invasive plants.

To learn how to identify and report target species, visit

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