The Importance of Invasive Plant Species Management

Invasive plants exist as both herbaceous and woody plants, which may be native or exotic, and tend to spread very rapidly while negativity affecting the health and productivity of the woodland. Generally, the term “invasive” refers to species which are exotic or non-native, however, “invasive” can also refer to a native plant’s aggressive growth and reproductive behavior, and ability to outcompete other native species. The longer growing season and shorter dormancy period of an exotic/non-native invasive species allows them to outcompete our native species for the same space, water, sunlight, and nutrients. Managing invasive plant species is important because without human intervention, the regeneration and production of native species which are vital to wildlife and our economy will struggle and deteriorate, dramatically changing and destroying native ecosystems.

Methods for Controlling Invasive Plants

The specific prescription for invasive plant treatment is determined by the target species and the extent of the invasion. Invasive plant control usually involves either mechanical removal or chemical treatment, but often times even a combination of the two.

Chemical Control

Invasive species control by herbicide treatment can be conducted through the use of backpack sprayers, ATV/UTV or tractor-mounted sprayers, or even hand sprayers to selectively target invasive plants. The specific herbicide application method is dependent on the target species and layout of the property. Herbaceous invasive species are generally treated by foliar spraying whereas woody invasive species can be foliar sprayed, basal-bark treated, or treated using the cut-stump or hack and squirt method. Foliar spraying invasive plants involves spraying the leaves of the plant during its active growing season. Basal-bark treatments involve spraying the base/stems of an invasive plant with an herbicide suspended in oil. With the cut-stump method, the plant is cut at the base and then the stump is treated with herbicide. The hack and squirt method is usually used to control larger, invasive trees and involves cutting into the bark and then spraying a strong herbicide mix into the cuts. The recommended herbicide mixes to utilize vary by the target species and selected application method. It is recommended to consult with and utilize the services of a licensed herbicide applicator when dealing with herbicides, not only for health and safety purposes, but because using the wrong herbicides may fail to kill the invasive plants or may even cause them to reproduce and spread more rapidly.

Mechanical Control

Invasive plants can be mechanically removed by the use of chainsaws or brush saws, or heavy machinery. Whenever controlling invasive plants with mechanical methods, it is recommended to treat the stems/stumps of woody invasive plants with herbicide, to prevent resprout by killing its root structure. If the plant invasion is severe enough, a mulching head attachment on a heavy piece of equipment such as a skid steer or excavator, can be utilized to completely clear an area. Once again, it is recommended to conduct follow-up treatments with herbicide to control resprouts. Heavy machinery can also be utilized to create access trails so the invasive plants can be foliar sprayed more efficiently by the use of backpack sprayers or mounted sprayers. Again, it is recommended to consult with and utilize the services of a licensed herbicide applicator when dealing with herbicides.