Jacques Wirtz (born December 31, 1924, Antwerp, Belgium—died July 21, 2018, Schoten) was a Belgian landscape designer who created more than 100 gardens and was hailed as one of the most talented and influential landscape designers in Europe.

When Wirtz was 12 years old, he moved with his family from Antwerp to an area outside the city, where he was deeply influenced by the natural beauty of the countryside. He studied landscape architecture at a horticultural college in Vilvoorde before starting his own business growing and selling flowers and maintaining local gardens. In 1950 Wirtz designed his first complete garden, in a style inspired by the gardens of his childhood as well as by those he had seen on visits to other European countries and to Japan. As Wirtz created more gardens, he came to be known for designs that complemented instead of concealing the natural surroundings; he favoured flowering plants, grasses, clipped trees and hedges, and water rather than the man-made materials that adorned many other modern gardens.

Wirtz’s career received a boost in the 1970s after he won a competition to design the garden for Belgium’s pavilion at the International Exhibition in Ōsaka, Japan. During this time he also designed the campus of the University of Antwerp, a plan that featured an ivy ground cover and an abundance of flowering trees. Wirtz gained wider recognition in the early 1990s when he won a contest to redesign the Carrousel Garden, which connected the Louvre Museum in Paris with the 63-acre (25-hectare) Tuileries Gardens, redesigned in 1664 by the celebrated French landscape architect André Le Nôtre.

Wirtz continued to work in the early 2000s, usually with one or both of his two sons, who shared in his business. Among the most significant of his projects were Jubilee Park at London’s Canary Wharf, the planting of which was completed in 2002, and the 12-acre (5-hectare) walled garden at Alnwick Castle in Northumberland. A spectacular undertaking featuring waterfalls and Wirtz’s famous mass plantings of geometric-shaped hedges of beech, box, hornbeam, and yew, the Alnwick Garden was under construction for most of the first decade of the 21st century.