Partial sun (n.): In care instructions for plants, there will usually be an indicator of how much sun a plant needs to grow well. If a plant requires partial sun or partial shade, it needs 3 hours of direct sunlight every day. It doesn't mean that the plant should have no direct sunlight. Many balcony container gardeners have problems getting enough sun. Read more about plants that thrive on shady balcony gardens at "25 Plants for Shady Balconies."