Testing the winter hardiness of selected chrysanthemum cultivars of Multiflora type

Over the course of 2007–2013, 19 selected cultivars of Chrysanthemum × grandiflorum were tested. Testing was conducted during two seasons under field conditions and on potted plants in the freezing chamber at temperatures –8, –10 and –12°C. It was found that frost hardiness of chrysanthemums of Multiflora type can be reliably determined at a temperature intervention of –8°C. The field trials and tests in freezing chamber revealed that cv. Vlasta did not overwinter. In field trials, the most winter hardy cultivars were Zina, Berta, Mína, Dorota, Estela, Tereza and clone 912, which are possible to grow as short-lived perennials. Cvs Marika and Tereza showed the best frost resistance in the freezing chamber and the best survival results after simulating spring frost.