On a quiet side street, Dutch landscape architect and designer Ronald van der Hilst tends to a richly layered, historic church garden

To achieve a feeling of abundance, landscape architect and designer Ronald van der Hilst planted beds with multiple individual species rather than big groups of one kind. The walls of Antwerp’s Sint-Joriskerk (St. George’s Church) rise in the background.

For Ronald van der Hilst —the Dutch landscape architect and designer based in Antwerp—one garden in particular celebrates his calling. It just so happens that he lives in a renovated 19th-century coachman’s house across the street.

The site is a hidden space known as Hortus Conclusus, after the Latin for enclosed garden. Historically, such spaces were often features of religious buildings around the world including monasteries and convents, keeping animals out and fresh water, herbs, vegetables, and flowers safely inside. This one belongs to St.…