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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