By Luke Gervase, Project Ecologist at GEI Consultants, Inc
In July 2021, GEI Consultants, Inc. (GEI) licensed pesticide applicators conducted a site visit at the Town of Brookhaven West Meadow Beach in Stony Brook, NY to identify current populations of perennial pepperweed (Lepidium latifolium). Perennial pepperweed is a highly invasive plant that favors upper coastal wetland habitats and has been documented at two sites on the north shore of Long Island. GEI staff employed wicking and brushing herbicide application methods on target plants to ensure little to no collateral damage to any desirable species in the area. While herbicide applications may not always be a fitting form of control, it was determined to be the preferred method of controlling perennial pepperweed in this location since past hand-pulling efforts were not able to fully eradicate this species.
Perennial pepperweed can reproduce readily via seed and rhizomes, and because of this, effectiveness of mechanical and physical controls is limited since those methods may increase the risk of further spread. Due to the persistent nature of this plant, its abundance at the job site, the aggressive method of growth and spread, and the limited efficacy of other control methods, a targeted herbicide application was chosen as the best method of control.
One advantage of chemical use in this scenario is that with proper timing of application, perennial pepperweed would not be able to produce seed before the herbicide kills the target plant, effectively eliminating that method of reproduction. Chemical control also opens available habitat to allow more desirable native plants to infill and restore the area. Chemical control also offers a more effective and favorable outcome as compared to the effort and labor required for manual removal. Repeated herbicide applications allow for populations of dense challenging invasive plants such as perennial pepperweed to be reduced to manageable levels, to a point where other methods can be utilized in a more fiscal and ecologically responsible manner.
