Sorry, I didn't mean to imply that there was anything false about your statement. I don't remember what my point was, so I should have written it down. It might just have been trivia.
You probably meant that technically, even the trees like ginkgo or all the oaks and maples imported from afar are useful - they can withstand the ufriendliness of city life. I agree. It is just a different kind of usefulness that potato and cucumber have, and back then there was no way to weigh costs and benefits of introduction. (The usefulness of a cactus is yet another thing.) Or you could mean that having a rich botanical garden was a status thing for a capital; an obligatory research facility for a self-respecting university. It should be still some...
I think we need a discussion thread for the californian drought going on. I would like to compile information in the main post and would like help compiling it. If we really are proud to be effective altruists then this is an area we should really figure out.
Any one have any good ideas on how we can help?