Do the experiments have to be Bio/veg related, or can I post up some of the things I've been doing to my neighbours?
I think a section with a 50 post rule would be an excellent idea, may be have an experiments section, general chatter section, for other things that you don't want every tom dick and harry reading, and a eugenics section.
As it is, most on here would qualify for access, but as the forum becomes bigger, it would find its value.