Disposal methods for invasive alien plants
In order to prevent the escape of ornamental plants from gardens, education and awareness raising about the problems of invasive species in the natural environment is essential. Safe and effective disposal methods for garden waste is an important aspect to educate the public on. Many invasive alien plants can be spread via dumping of garden waste into the natural environment. In the first experiment, 8 ornamental invasive alien plants were selected that either disperse by growing from cut stem pieces (Cornus sericea* (Cornaceae), Buddleja davidii* (Scrophulariaceae), Parthenocissus quinquefolia (Vitaceae)) or through subterranean parts, such as rhizomes and tubers (Solidago canadensis*, Solidago gigantea* (both Asteraceae:), Rudbeckia laciniata (Asteraceae), Helianthus tuberosus* (Asteraceae), Symphyotrichum novae-angliae). Three storage treatments available to gardeners were used: drying, composting and storage in black bin bags. After five months of storage, the plant material was planted and observed for growth. Drying and composting were highly efficient for disposal, as the conditions destroyed the majority of the plant material. However, storage in a black bin bag was inefficient because it did not kill any of the plant species tested. In the second experiment, 5 invasive woody species (C. sericea, B. davidii, Acer negundo (Sapindaceae), P. quinquefolia, Forsythia x intermedia (Olaceae)) were used to evaluate if shredding is a good disposal method. The shredded material (ranging from < 1 cm up to 3 cm) was stored either fresh or dried. In the case of the latter, there was no regeneration of fragments for any of the species. For fragments stored as fresh material, all species developed green shoots, though these were in small numbers for A. negundo, B. davidii and C. sericea. For Forsythia x intermedia and P. quinquefolia, some fragments > 1 cm showed rooting. Therefore, the study could propose some solutions to gardeners to dispose of some plant material in a safe way.
* EPPO List of Invasive Alien Plants
Krajšek SS, Bahčič E, Čoko U, Koce JD (2020) Disposal methods for selected invasive plant species used as ornamental garden plants. Management of Biological Invasions 11, 293-305.