Follow this test to determine level of light in a particular location. Hold your hand 12 inches above a sheet of paper. If there is a definite shadow, the level is classified as high light. If there is a fuzzy shadow, the light level is medium. And if there is no shadow, light level is low.
Special care is required to produce blooms.
Poinsettia, kalanchoe and Christmas cactus flower only when day-length is less than 12 hours. However, most flowering houseplants are not sensitive to day-length. Variegated leaves have pale or colored sections that contain no chlorophyll. Chlorophyll is necessary for photosynthesis. Therefore, the rest of the leaf must be exposed to more light to compensate for the nongreen areas that cannot contribute to this life-sustaining process.