Water Hyacinth ~ Floating Pond Plant

water hyacinth floating pond plant

water hyacinth

Water hyacinth floating pond plants, or Eichhornia Cressipes, are beautiful but destructive in the wrong climates. It is an indigenous species that originated in Amazon Basin (South America). Since the 1800s, it has mainly spread to the subtropics and tropics in natural waterways.

Flower stalks can grow up to six inches in length. The rosettes that rise from the center of the rosettes in spring produce the flower stalks. Each plant can hold around 20 beautiful purple flowers.

These flowers can be cut and placed into indoor vases.

Water Hyacinth in Ponds

The purple flowers of the tropical water hyacinth, borne above the water, can quickly fill a pond. Their waxy, green, scoop-ended stems keep them afloat by air-filled chambers that bulge within their hollowed stems. They are helpful in water purification and the reduction of algae.

How to Plant Water Hyacinth in a Pond

Water hyacinth plants can be placed in your pond, but they must not float into the pond skimmer. To prevent the skimmer from drawing in the floating hyacinth, you can set them around the pond’s edge or inside lily pads. If there are no lily pads or boulders to keep them in place, you could use a fishing line strung across the pond to hold them in place.



Growing Water Hyacinth 

It is pretty straightforward to grow water hyacinths. They don’t require any special care once they are established. However, they need to be trimmed occasionally to prevent them from taking over the entire pond. A colony of water-hyacinths will double under ideal conditions every 8 to 12 days.  Trimming is as simple as clipping an offshoot.  No special knowledge is required. 

Water hyacinths require full sun and warm summer temperatures. You can introduce them to your pond by placing bunches of plants on the water’s surface. They quickly soak up the water and start to grow. When they cover more than 60% of the pond’s water surface, thinning of the plants is needed.

The U.S. Department of Agriculture plant hardiness zones 8 to 11 (find your zone) are ideal for water hyacinths. These plants are best grown in areas where they can be controlled by cold winters. These pond plants can become invasive in warmer regions. Water hyacinth can be overwintered indoors in a sunny location, but it is expensive to replace each year. They are not worth the effort to maintain over winter for most gardeners.


Caution: In areas with mild winters, water hyacinth pond plants can be invasive. In several states, the plants are prohibited. They can grow to dense mats and choke out native species once they get into waterways. The thick growth of water hyacinths can trap boat motors, making it challenging to use lakes infested for recreational purposes. The plants block sunlight and reduce oxygen levels, leading to the death of fish and other aquatic wildlife.

States that are currently illegal to own water hyacinth:

  • AL
  • AR
  • AZ
  • CA
  • LA
  • FL
  • ID
  • IL (Chicago)
  • NE
  • PR
  • MS
  • SC
  • TX
  • WI

Is Water Hyacinth Harmful to Humans?

While there is no direct threat to humans, water hyacinth can be harmful in that it can destroy ecosystems that we depend on.  Also, provide a habitat for mosquitoes that could carry West Nile Virus.

Why is Water Hyacinth a Problem?

The water-hyacinth can block waterways restrict boat traffic, flood control, and wildlife use. This exotic pest plant creates a dense canopy over the water surface and shades native submerged plant species. It can also uproot important native emergent species.

Is Water Hyacinth Good for Fish

The water hyacinth has leathery, creeping foliage that works to cover the pond’s surface. The leaves provide shade, and the roots help filter the water. They also provide spawning areas for the fish and a buffer zone. It is also an excellent water clarifier. Koi loves to nibble on its root systems.

Do Koi Fish Eat Water Hyacinth?

Larger koi can eat the roots of your water hyacinth. This reduces the plant’s ability to absorb nitrogen and decreases its benefits to water quality. As the plants starve, they will become yellow and then shrink.

Last Updated on February 27, 2022 by Davin