Further discussion regarding invasive plants is needed in response to the letter from Amy Steffen (“Invasive Plants Have Benefits”) in the November 2020 Shuttle. Invasive species (plants and animals) cause considerable economic and ecological damage to ecosystems, agriculture, forestry and other industries in the United States. We should not be promoting invasive plants (e.g., Bishops weed) as having benefits unless they provide a real value to society (such as being a major food crop) that clearly outweighs the cost of their ecological damage.
Also, sometimes application of herbicides is required for successful eradication of large colonies of invasive plants (e.g., Japanese knotweed). Of course, herbicides should be used sparingly, and spot sprayer technology has advanced to make it easier to target only invasive plants. This technique has been used successfully around the country to restore native ecosystems.
In addition, Amy’s letter references a book (“Beyond the War on Invasive Species” by Tao Orion) which states that invasive plants get established on disturbed land where conditions no longer support native plants. In fact, many native plant species are specialists at colonizing disturbed sites. A disturbed site may become dominated by invasive plants if native seeds have not been introduced or had an opportunity to colonize the site.
Homeowners should be able to find a native plant species that will grow on any site condition in their yard. To learn more about the importance of native plants, their adaptability, and the harm of invasive plants, Doug Tallamy, a key proponent of the modern native plant movement, has authored several books (“Bringing Nature Home,” “The Living Landscape” and “Nature’s Best Hope”), all of which I highly recommend.
— Mark Eberle