Chrysanthemum stunt virus (CSV) is widespread wherever chrysanthemum cultures are grown, causing severe stunt and deterioration in quality. Chrysanthemum chlorotic mottle virus (ChCMV), causing a slight reduction in growth, occurs only to a limited extent. Establishment of healthy plants has been carried out with divergent results, and in many cases without success. A more reliable method of producing healthy chrysanthemum plants was carried out by heat treatment and meristem-tip cultures. Storing of chrysanthemum, carnation and pelargonium plants in tubes at low temperatures as well as hypobaric conditions was attempted. CSV was inactivated increasingly with the decreasing size of the meristem-tip in connection with disinfection of the scalpel, making it hot between the individual meristem-tips. Meristem-tips from the terminal buds have given the greatest number of CSV-free plants. Heat treatment of either the mother plants or the meristem-tip plants in tubes had no definite influence, nor had the addition of auxin (2,4-D) to the nutrient solution. ChCMV was only inactivated in a single plant by similar treatments. Storage of plants in tubes at low temperature was possible, comprising carnation during one year, chrysanthemum temporary during 5 mo. and for pelargonium during 7 mo. The stored plant material was still suitable for cutting production after further culturing at optimal conditions. Hypobaric storage had no advantage either for carnation or chrysanthemum.