The number of flowers in young plants of three gloxinia cultivars was not increased when irradiance was increasedto 18 W m-2 in the wavelength ranges of 400–1000 nm under winter conditions, although days to marketable stage (flowering) was shortened (Grimstad, 1987). When plants are placed under unfavorable temperature and light environments, floral initiation and development will be affected, and ultimately the number of flowers will be reduced, perhaps due to a loss of flowers as reported in the Oriental hybrid lily (Lee and Roh, 2001). Therefore, it is recommended that S. cardinalis be grown at low temperature and reduced irradiance. The degree of shading or level of irradiance should further be tested depending on the location of production.