Green fountain grass (Pennisetum setaceum) Fountain grass grows up to 5′ in large clumps of long, narrow leaves with foxtail-like plumes in the summer. … PlantRight only considers the parent species of Pennisetum setaceum to be an invasive plant in California, and only counts those plants in the nursery survey.
When established they can tolerate dry periods but require moist soil when becoming established. As with many other ornamental plants, they do not like constantly soggy or wet soil, which can lead to root rot and other plant diseases. So be careful not to overwater!