Illustrated manuscripts & early depictions of landscapes in portrayals of Biblical gardens give us a glimpse of gardens - real, symbolic, familiar, & imagined by artists & their clients during those periods.
This painting copies those where the Virgin Mary begins to appear in contrived, formal gardens & in more natural cultural landscapes in the 1300s. One of the garden depictions is the hortus conclusus. Hortus conclusus is a Latin term, meaning "enclosed garden." Hortus conclusus is both an emblematic attribute & a title of the Virgin Mary in Medieval & Renaissance poetry & art, appearing in paintings & manuscript illuminations as well as a type of an actual garden form of the period which was enclosed both symbolically & actually.
The term hortus conclusus is derived from the Vulgate Bible's Canticle of Canticles (also called the Song of Songs or Song of Solomon) 4:12, in Latin: "Hortus conclusus soror mea, sponsa, hortus conclusus, fons signatus" ("A garden enclosed is my sister, my spouse; a garden enclosed, a fountain sealed up.") This format provided a linguistic culture of Christendom, expressed in the Song of Songs as allegory where the image of King Solomon's nuptial song to his bride was reinterpreted as the love & union between Christ & the Church, the mystical marriage with the Church as the Bride of Christ. The verse "Thou art all fair, my love; there is no spot in thee" from the Song expresses confirmation of the doctrine of Mary's Immaculate Conception-birth without Original Sin ("macula" is Latin for spot).
Christian tradition asserts that Jesus Christ was conceived by the Holy Spirit to a young Mary miraculously without disrupting her virginity. As such, Mary in late medieval & Renaissance art, illustrating the Perpetual Virginity of Mary, was shown in or near a walled garden or yard. This was a representation of her Immaculate Conception, & also of her being protected, here by a wall & hedge, from sin.