Pfiffner, Lukas; Laurent, Jamar; Cahenzli, Fabian; Maren, Korsgaard; Weronika, Swiergiel and Lene, Sigsgaard (2018) Perennial flower strips – a tool for improving pest control in fruit orchards. 2018 edition. Technical guide. Research Institute of Organic Agriculture (FiBL), CH-Frick.