It is Invasive Species Awareness Week!

Posted on: July 15th, 2016 by Caroline Stupple

Inva­sive Species Aware­ness Week (ISAW) is a col­lab­o­ra­tion between mul­ti­ple regional, state, and fed­eral agen­cies. ISAW seeks to enhance aware­ness of inva­sive species and pro­vide peo­ple with tools for man­age­ment. Locally, through­out the Catskill area, the Catskill Regional Inva­sive Species Part­ner­ship (CRISP) pro­vides edu­ca­tional mate­r­ial and sup­port for inva­sive species removal. A focal species for man­age­ment has been Japan­ese knotweed.

Japan­ese Knotweed was intro­duced to the United States some­time in the late 1800s and was touted as an excel­lent gar­den orna­men­tal plant. It was soon iden­ti­fied as an inva­sive species due to its aggres­sive spread through­out and beyond the region of intro­duc­tion and its ten­dency to out­com­pete native plant species.  In Ulster County, though we are not alone in this strug­gle, we have seen the tremen­dous spread of knotweed espe­cially along stream sides. Its migra­tion is highly effi­cient along these buffer zones due to its abil­ity to reestab­lish a new stand from a small root frag­ment washed downstream.



Japan­ese knotweed stand along left side of stream. Photo by Ulster County Soil and Water Con­ser­va­tion District.


Knotweed can be iden­ti­fied by its large heart-shaped leaves, hol­low bamboo-like stalks, and the clus­ter of white or cream col­ored flow­ers. Stands of knotweed are immensely dif­fi­cult and time con­sum­ing to erad­i­cate, how­ever, it can be man­aged with vig­i­lance and patience. Among other man­age­ment plans, CRISP sug­gests rou­tine and con­tin­u­ous removal of knotweed stands or her­bi­cide injec­tions into the stocks.  Man­ual removal of knotweed can be time con­sum­ing, as removals must reoc­cur 2–3 times every year for 3 or more years. Addi­tion­ally, due to the ease with which knotweed spreads the herba­ceous mate­r­ial must be dis­posed of prop­erly; dis­posal includes let­ting the mate­r­ial dry out and burn­ing it when dried. Injec­tion of the her­bi­cide is also time con­sum­ing and may not be prac­ti­cal for a large knotweed stand. The her­bi­cide must be injected into each stalk at approx­i­mately the 3rd node on the stalk dur­ing the late sum­mer and early fall months.

The bat­tle against Japan­ese knotweed is best fought on many fronts and with coor­di­na­tion and efforts from as many peo­ple as pos­si­ble. If you would like to know more about how you can help with Japan­ese knotweed erad­i­ca­tion and man­age­ment in your area, or would like to learn more about other inva­sive species in the area, please click here to be directed to the CRISP web­site. If you would like to learn more about the annual Inva­sive Species Aware­ness Week and to get more infor­ma­tion about New York inva­sive species, please click here.

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