Potentially feral grass species in ornamental plant- and seed trading: is this the beginning of a new spread of invasive alien plants?
A lot of grass species have been introduced by human activities, and many of them have been able to establish as neophytes or even become invasive. Several introduced species will increasingly gain importance for use as ornamentals, due to the trend to grass-gardening in the post-war period. Some of them will probably become feral or even invasive. Completing the catalogue of grass neophytes published in the last issue of this journal (Englmaier & Wilhalm 2018), such species are presented here, some of them traditionally used in gardening, but an increasing number just recently offered. Gardeners and citizens with floristic interests shall be encouraged to observe occasional spread and even invasiveness of these species. Only sufficient knowledge of species and their spreading behaviour will help EU officials to introduce regulatory interventions. Therefore, suitable aids for identification are recommended. For practical gardening, some hints for the use of ornamental grasses and prevention of their uncontrolled spread are provided.