ABSTRACT
Campanula pyramidalis requires vernalization at temperature of about 5 to 8° for 6 to 8 weeks, followed by an absolute long day requirement for a minimum 14 to 15 hr for flowering. The plant is of little commercial value, although the elongated stems of 100 to 150 cm grown and bound in a circle, with 100 or 200 flowers, could form a nice pot plant and are showy in the garden. Propagation is usually done from seeds, which germinate well at 20°C under light. Under natural conditions, plants grow as rosettes during the first growing season and elongate and bloom in spring or summer of the next year. After blooming, growth is continued by lateral rosettes. After fulfillment of the low-temperature requirement, long day are necessary for bolting; months of short day after vernalization may devernalize most of the plants. Preliminary results4 show that neither the low-temperature requirement nor the long day requirement for bolting can be substituted by GA.
