Tips for growing Water Hyacinths in your garden pond or water garden
Water Hyacinths are fast growing, floating perennial flowers that grow in ponds, streams and waterways.
Although Water Hyacinths are beautiful flowers, they’re an invasive species in many areas so it’s essential to learn how to properly manage and control their growth before planting them in your pond.
This post contains affiliate links. Please read the disclosure for more info.
Water Hyacinths (Eichhornia crassipes) are native to South America and they’re one of the world’s fastest growing plants.
If left to grow wild in waterways or streams they can quickly form a thick mat on top of the water, so they need to be managed closely.
Water Hyacinths are banned in many areas, so you’ll need to check if you’re allowed to grow them in your area.
When do Water Hyacinths bloom?
Water Hyacinths bloom from late summer to early fall and each plant will produce about 20 flower stalks that reach up to 6 inches (15 cm) tall.
The flowers are pale purple and one petal on each flower has a yellow spot.
How much sunlight do Water Hyacinths need?
Water Hyacinths prefer to grow in a position with full sun and warm water temperatures.
How tall do Water Hyacinths grow?
Water Hyacinths can grow 2 to 3 feet (60 to 90 cm) tall.
Where do Water Hyacinths grow?
Water Hyacinths grow best in areas where minimum temperatures are above 54 °F (12 °C) and maximum temperatures are below 95 °F (35 °C). 
In cool climates, they can be grown in large containers and overwintered in a greenhouse or grown as annuals.
Planting Water Hyacinths in your pond
The easiest way to grow Water Hyacinths is to scatter a few cuttings in your pond. In the right conditions they’ll grow quickly.
For a small pond, one plant is usually sufficient because they spread rapidly.
The roots float in the water but they can also burrow into the soil.
How to stop Water Hyacinths becoming invasive
If you’re planning to grow Water Hyacinths in your backyard pond, it’s a good idea to grow them in a partitioned off area so that they can’t spread out and cover the entire surface of the pond.
The plants will need to be cut back if they cover half of the pond.
Each water hyacinth plant can produce up to 5000 seeds and the seeds can germinate in as little as 3 days. 
Are Water Hyacinths frost tolerant?
Water Hyacinths are not frost resistant. The leaves are killed by frost.
Are Water Hyacinths toxic?
The plants are toxic to dogs, cats and horses, so it’s not a good idea to grow them if you have pets.
Can Water Hyacinths kill fish?
If Water Hyacinths become overgrown and cover the entire surface of a pond or lake they can block out sunlight, alter the pH, temperature and oxygen levels in the water and reduce gas exchange at the surface of the water leading to fish kills.
With some careful management, these beautiful floating flowers can be an attractive addition to your garden pond.
Have you tried growing Water Hyacinths in your water garden or pond? Let me know in the comments below.
Are you on Pinterest? I have boards dedicated to Garden Ponds and Water Garden Plants that you may enjoy.