A method to identify potential cold-climate vine growing sites: a case study from Røsnæs in Denmark

A method for surveying the suitability of cold climate vine growing sites in Denmark is presented with focus on limiting growth parameters. The four most important parameters are identified on the basis of literary studies and discussions with approximately 150 vine growers in Denmark. These are: i) Sum of growing degree days (SDD), ii) Risk of frost damage, iii) Number of sunshine hours during growth season, and iv) Soil drainage. A two-step method based on GIS and already existing climate, soil, and topographic data was implemented. First the most suitable areas in Denmark for vine growing were located on the basis of nation-wide climatic data on the sum of degree days and risk of frost. Within the most suitable areas a detailed survey of the amount of sunshine, topography, drainage and soil was carried out on the Røsnæs peninsula in north western Zealand, and eight well-suited vine growing terroirs were identified of which three were highly recommended.