|Cortaderia selloana in Virginia
|Huge Cortaderia selloana on sidewalks in Virginia
Unfortunately, many people select ornamental grasses without any consideration about their potential for harming the environment, and the horticultural industry itself may exacerbate the problem by continuing to sell plants that have been proven to be invasive. This lack of awareness extends to even reputable botanical gardens and arboretum, and I have repeatedly seen some institutions make heavy use of ornamental grasses like Miscanthus sinensis. Granted, these non-native grasses are often beautiful, but this dependence on such cultivars creates problems due to the potential invasiveness of the species.
|Escaped Cortaderia selloana in Florida
It's not all black and white though. What may be invasive in one region, might be relatively benign in another clime. For example, Imperata cylindrica is one of the most invasive grass in many subtropical and tropical areas in the world, but a red cultivar (called Japanese Blood Grass) is relatively harmless in colder areas, even though it can allegedly revert to an all-green invasive form when grown in a more suitable climate.
|Large Miscanthus sinensis in parking lot of suburban strip mall in NJ
However, a species that may at first seem non-invasive can become invasive over time. This might have been the case with the popular Cortaderia selloana (pampas grass) from South America.
|Escaped Miscanthus sinensis at forest edge in NJ
|Arundo donax in an arboretum in NJ
- Make it illegal for the retail industry to sell invasive species, and enforce the law.
- If possible, sell sterile cultivars of any non-native species.
- Continue to inform people about the problems associated with non-native ornamentals, even those that do not seem to be currently invasive.
- Promote the use of native ornamental grasses, such as Panicum virgatum, Schizachyrium scoparium, and Andropogon gerardii cultivars. Emphasize not only the environmental reasons for using these, but also their beauty and adaptability.
|Cortaderia selloana in North Carolina parking lots
Lambrinos, JG (2004). A tale of two invaders. The dynamic history of pampas grass and jubata grass in California. Cal-IPC News. Vol. 12, Nos. 3/4