On a sunny day, only about 1 percent of the light received by a leaf will be used in photosynthesis. The rest will be reflected, transformed into heat or used for other plant processes. On the other hand, photosynthetic production will be dramatically cut back during cloudy weather or other low-light situations. Fortunately, not all plants must have maximum light intensity for good plant growth. The optimum light level depends on the species of plant.
Some plants require as little as one-tenth of full sunlight.
This is why some plants, such as impatiens, are considered shade plants, while others, such as petunias, are considered sun plants. Houseplants also vary in their light needs. Because light levels inside the home are generally quite low compared to outdoors, we often think of the houseplants in terms of how well they adapt to low light. Most houseplants will grow best in as much light as you can supply in the typical home. But there are a few plants, such as pothos, snake plant, dracaena, and Chinese evergreen, that can adapt quite well to low light though they may grow more slowly.