Photo: Diane Edwardson, October 22, 2011. It's best to pull the Castor Bean seedlings at this stage, before the roots get deep. Let them dry out on pavement; they will just grow back if pulled and left on the dirt. (Click on photo to enlarge.)
We've written lots about Castor Beans, a highly toxic (this one can kill an adult with just a few beans), non-native, invasive plant. If left unchecked, they will quickly take over a hillside and damage public staircases. Read more in a post from 2010, as well as on California Invasive Plant Council's website.
Disclaimer: The Corralitas Red Car Property Blog prefers to quote reliable sources, such as Calflora and California Poison Control, on the issue of toxicity. We often get email suggesting some plants are edible. If you are eating your way through the Red Car Property, we DO NOT recommend you eat any plant you find in the Red Car Property neighborhood without first doing your own research.