Two Ornamental Grasses Invasive!

UC Master Gardener Program Statewide Blog

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News and updates from the statewide UC Master Gardener Program office.

Author: Pamela M. Geisel

Published on: January 14, 2011

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Two grasses have recently been discussed by PlantRight and other organizations with concerns about invasive ornamental grassses. Mexican Feather Grass (Nassella tenuissima) and Chilean Needle grass (Nassella neesiana) are two grasses in particular that have invasive tendancies. Both are being phased our of production by the nursery industry and alternatives are suggested. A recent publication describes the potential extent of invasion of Chilean needle grass, Nassella neesiana (Cyperales: Poaceae), in the United States. Under current climate conditions, researchers predict that N. neesiana may become invasive on the west coast and in the coastal southeastern United States. The publication also describes the weed's potential distribution based on six future climate scenarios.

Nassella neesiana is unpalatable to livestock and its awns penetrate the fibers, skin, and muscle of grazing animals, resulting in reduced market values for these products. Native to South America, N. neesiana is also known to occur in the United Kingdom, France, Italy, Spain, Australia, and New Zealand. In the United States, N. neesiana is known to occur in Alabama.

Blond ambition grass, Photo by High Country Gardens

A suggested alternative to both grasses might be Bouteloua gracilis "Blond Ambition". (See photo left) Currently it is availble through High Country Gardens at: http://www.highcountrygardens.com/catalog/product/27061/

References:
1. Bourdôt, G. W., S. L. Lamoureaux, M. S. Watt, L. K. Manning, and D. J. Kriticos. 2010. The potential global distribution of the invasive weed Nassella neesiana under current and future climates. Biological Invasions DOI: 10.1007/s10530-010-9905-6. Last accessed January 6, 2011, from http://www.springerlink.com/content/53hn2q843272qu06/fulltext.pdf.

Comments: 7

Comments:

by Sharon R McDonnell

on January 14, 2011 at 12:35 PM

Thanks for this info. I like being informed and kept up to date. Thanks.
Sharon

by Carolyn Neumann

on January 15, 2011 at 12:50 AM

Glad to see that, as it is an out of control plant and I suspected it was just a matter of time. I will remove it from my landscape designs where it was placed unknowingly and convey the information to others in the field of nursery and design.

by Carol Haverty

on January 20, 2011 at 9:27 AM

thank you for offering altrnatives to invasive plants, this helps consumers and educators help the home owner and others make better choices.

It would be grand to see these same solutions offered in a timely manner for water thirsty horticultural traditional nursery stock.

by Beatrice Ross

on January 23, 2011 at 2:26 AM

I recently got a cuttings and planted a few of the Mexican feather Grass from a Master Gardener colleague on my front lawn. Now I will replace it with Blond Ambition. Thank you.
Beatrice Ross

by Kathi Perez

on February 7, 2011 at 9:18 AM

great information to know. i will not suggest these plants for landscaping. is there a local source for blond ambition?

by Bill Donovan

on March 3, 2011 at 12:09 PM

I installed a dozen Mexican feather grass at my place in the desert. I have since suspected that they might be invasive (too many volunteers). I will replace them the next time I am there.

by Carvill Veech

on March 7, 2011 at 7:14 PM

Thank you. I have some planted and have enjoyed it except for the hundreds of unwanted volunteers. I am phasing it out and now will not pass it along.