The food we eat is not only concrete, but also abstract, not referring to the state of its ripeness. Since fruit and vegetables are such a part of our daily life, they have entered our language also.
In a loving family, a person can refer to his/her significant other as a sweet pumpkin and child as the apple of his eye. By contrast, being a couch potato is bad while being a vegetable is tragic. A Georgia Peach is one of the special pretty girls from the American South, with bright red cheeks (at least in my imagination). It is obvious that one should not buy a lemon because it is a very bad car. Someone who lets out a raspberry in public is embarrassed by the smell and can drive people bananas or crazy. It will definitely get you into a pickle, a difficult situation.
French also has its green-based expressions. Mon chou-chou is a wonderful endearment which literally means my little cabbage. I suppose that it is no more illogical than calling someone a pumpkin. A woman referred to as a pruneau, a plum, is not flattered as it means that she has many wrinkles. A bad movie is a navet, a turnip, while raconter les salades means telling lies, literally telling lettuces. If you don’t have any radis, radishes, you are broke. (My appreciation to http://www.francaisfacile.com/exercices/exercice-francais-2/exercice-francais-7627.php for some of the French terms.)
I would be interested in hearing about other imaginative uses of fruits and vegetables.