The horticultural industry may sell cultivars of invasive plants that produce fewer seeds. These are billed as non-invasive cultivars. According to new research, however, many of these non-invasive cultivars are still invasive. Tiffany M. Knight of Washington University and co-authors from the Chicago Botanic Garden conducted population modeling and found that even a 95 percent reduction in viable seed production of an invasive plant still can result in invasion. Moreover, the offspring of cultivars do not usually “breed true” especially if they cross with plants from feral populations. The results of their study are published in the October 2011 issue of BioScience.
In short, don’t buy cultivars of Japanese barberry, buckthorn, burning bush, etc.!