Producing a beautiful flower, the water hyacinth (Eichhornia crassipes) flourishes in freshwater habitats. Sunshine, heat and nutrient-rich water helps this floating plant grow and quickly multiply. It also has the potential of becoming a noxious aquatic weed.
Since water hyacinth appreciates warm air and water temperatures, sunlight plays an important role in maintaining a viable growing environment. The plants also need ample sunlight to make food in their leaves. Insufficient light slows growth, reduces the number of leaves and inhibits flowering.
Growing best in full sun with at least 10 hours of direct sunlight daily, water hyacinth still performs well in partial shade as long as it receives no less than three hours of sun. Bright, indirect light may sustain the plant, but it won’t prosper.
If you grow water hyacinth in a garden pond to provide attractive flowers, it must receive direct sunlight. Growing the floating plant to provide leafy texture only, or as a habitat for pond fish, shady garden areas may work. However, too little light and warmth causes plants to yellow and wither over time.