Photo: Diane Edwardson, June 12, 2015. Above ground, Castor Bean seedlings look like harmless 2" seedlings. Below ground, they've got a 6" tap root. If you pull it out and leave it on the dirt, it will grow right back within a day and double in size a day later.
Castor Beans are are non-native, invasive and in the past, have broken apart the Corralitas Public Staircase. They are a noxious weed that releases a toxic gas when it burns. Dispose of the seedlings, flowers and seed pods in your black trash can, NOT your green can. All parts of the plant are toxic and stems, roots, flowers of the plant can repropagate. They need to be eradicated. They clog waterways and hillsides and push out native plants.
Read more: California Invasive Plant Council.
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.