There is a history of
characters talking a big game and failing to deliver on execution. She was a florist. Do we have any evidence that she really knows anything? I am not an expert on this, but I think I remember an estimate of 1 acre of an established garden can feed 10 people. Figure an acre is about 220 feet by 220 feet.
I do not want to nitpick every little thing in the story. I am open to a lot of disbelief slack, but I do look at patterns and talking big and failing to deliver seems to be one. So, I am stuck with not knowing if it is a bug or a feature.