Yes, some varieties of fountain grass, particularly Pennisetum setaceum (Crimson Fountain Grass), have become invasive in parts of California. This invasive nature has led to concerns in natural ecosystems and wildland areas, particularly in arid and semi-arid regions of the state. The invasive characteristics of crimson fountain grass include its ability to self-seed prolifically, establish in disturbed areas, and outcompete native vegetation. Because of these concerns, some areas in California have taken measures to control or restrict the planting of certain fountain grass varieties, particularly in regions where they pose a threat to native ecosystems and wildfire risk. It's important to check with local authorities and follow any regulations or guidelines regarding the cultivation of fountain grass in your specific area to help prevent its spread and protect native habitats. Additionally, consider choosing non-invasive ornamental grass alternatives for landscaping in regions prone to fountain grass invasiveness. READ: Is Purple Fountain Grass Invasive