A Black Lagoon Case Study: Managing Common Horsetail in Northern New Jersey



Applicator’s Notes: In 2019, homeowners contacted Black Lagoon after recently purchasing their northern New Jersey property. Upon site consultation of this, .1-acre shallow pond (three feet maximum depth), it was determined that there was a significant infestation of Common Horsetail (Equisetum arvense), an aquatic relative of ferns. Being that this species of aquatic plant is not common at nuisance levels throughout much of our service area, several technical representatives were contacted to develop a management plan which was to be implemented in 2020.

A northern New Jersey residential pond was completely overrun with Common Horsetail during a 2019 site consultation; Photo courtesy of Christian Watkins, Territory Manager

What is Horsetail: Common Horsetail, Equisetum arvense, herbaceous relative of ferns. Distributed throughout much of North America, outside of the furthest southern states, dense rhizomatic root structures can make the plant hard to control/eliminate where unwanted. Growing best in moist soils, the areas in and around ponds are ideal for this plant to grow up to two feet in length. Like many nuisance aquatic plants, Horsetail is used as accents in many water gardens, where it can escape and be distributed to other waterbodies.

A closeup of Common Horsetail, Equisetum arvense.

Success Story: After filing for an aquatic permit through the NJDEP, an initial foliar herbicide treatment was made on May 18th, 2020. Proving highly successful, a follow-up treatment was performed two weeks after the initial treatment to capture the small number ( <5%) of plants that needed retreatment. Regrowth of the plants following the second treatment was minimal to non-existent. Being that a dense rhizome system is associated with Horsetail, monitoring of the waterbody and possible subsequent treatments are planned for 2021.

Happy homeowners! One month after implementation of an herbicide treatment program.