It's so weird to be out hiking in redwoods and come across a random stand of Pampas grass. It's like... did a landscaper get lost..? How did you get here?! Shouldn't you be in front of a Hyatt Regency??
Are people purposefully planting onion grass? I'm not in Cali... and granted some of my neighbors look like they've intentionally plated it all over their yard.... but I'm fairly certain it's not intentional.