It seems that the zucchini was chosen at random, but it is curious that squash means both squish and zucchini. I think that the choice is very bad for porting to Spanish, because this plant is idiomatically related to relationships, and in a bad sense. Giving gourds to one who has asked you out is a negative answer. Moreover, and this is independent of language, a courgette is a phallic symbol, so it could be understood as friends-with-benefits relationship. I think this is even worse than choosing the amoeba as a symbol of asexuality, because in Spanish it is the symbol of the lowest intelligence.