Rooted cuttings of Achillea filipendulina `Parker will flower without vernalization

Achillea filipendulina `Parkerʹ (Asteraceae) is a cut flower crop in Europe and the USA. It is grown mostly in open fields for several years. A. filipendulina `Parkerʹ has been reintroduced in Israel as a potential cut flower to export to Europe during late winter. Open-field cultivation results in summer flowering and to advance flowering to the wintertime, cooling and illuminating of corm and rooted cutting was tested. Cooling corms was found to advance flowering by several months but resulted in considerable losses of corms due to weakening during cooling. Cooling rooted cutting had no positive effect on flowering time and also weakened the cuttings. Both cooled corms and non-cooled rooted cuttings flowered early in response to added illumination.