BJBB -- they came back but not from seed....
In May 2013 I noticed that the raised bed which grew my BJBB in 2012 (first time) was peppered with "volunteers". I assumed these plants were from the seeds that popped from the dried pods that I failed to remove in a timely manner. I am sure that some of the "volunteers" are from such seeds. I have pulled a few of the plants and a former extension agent looked at them and he thinks that some of my BJBB plants are from last years roots and not from seeds that self-sowed. He said he could tell from the root structure. Now I did not get all technical with him so I do not know how he can tell these plants are perennial and not from seed. I can say that the stems on the plants that he thinks are perennial are about as thick as those "fat pencils" that kindergartners use. And those thick stem BJBB plants are super super productive.
My plan now is to heavily mulch this raised bed in early November when the vines die back and see what happens in spring 2014.
Has anyone here had their BJBB plants act like perennial?? I know there are lima beans that are perennial in certain zones but I am Zone 7B micro climate in a Zone 7A area.
If this continues I may never need to plant BJBB - but I would save some seed each year -- just in case.