This paper seeks to interpret the biblical metaphor of the hortus conclusus (closed garden) according to a Mariological projection, as presented iconographically in various Quattrocentro Annunciations. The author bases his interpretations on the exegesis developed by many Latin and Greek-Eastern Church Fathers and theologians, who considered this metaphorical expression of the Song of Songs to symbolize Mary’s virginal divine motherhood and perpetual virginity. Their textual interpretations of this doctrine helps elucidate the Mariological meaning in six Quattrocento paintings that include a more or less explicit “closed garden.” These six paintings present a closed garden as a visual metaphor illustrating the Mariological dogmas unveiled by the Church Fathers and theologians when explaining this biblical metaphor.