Jacques Wirtz (31 December 1924 – 21 July 2018) was a Belgian landscape gardener.
Wirtz was born in Schoten, a suburb of Antwerp.
His family were stockbrokers.
He studied landscape architecture at a horticultural school in Vilvoorde.
He was forced to work in a nursery in Germany during the Second World War.
He started his own business in 1950, as garden designer and later landscape architect.
He has four children.
His sons Martin (born 1963) and Peter (born 1961) joined the firm in 1990.
It is the largest landscape design business in Belgium.
Wirtz is particularly noted for his use of evergreens clipped to create undulating "clouds" of foliage, creating a green architecture that lasts all year, together with a retrained palette of herbaceous planting.
He believes that his gardens should preserve and enhance the spirit of place, rather than stamping his own mark on the landscape.
He came to public notice after being commissioned to design the garden for the Belgian pavilion at Expo '70 in Osaka.
Perhaps his largest public commission was the redesigned Jardin du Carrousel in the Tuileries Gardens in Paris, a long-running project which started in 1990 and was completed in 2004.