Water Hyacinth – a workhorse in a Colorado pond

outdoor fountains

Water Hyacinth Blooms

Water hyacinths put out soft purple blooms that can be from 4 inches to 12 inches tall! I have observed that the hyacinth in my pond does not bloom but the ones in my waterfalls do. My theory is that because they are very sensitive to water temperature, that the pond water is a little too cool.  The stream water is more shallow and therefore has warmer water. If you have blooming hyacinth in your pond, take a picture and shoot it over to us!  Also if you want your hyacinth to bloom try putting some in the stream or waterfall and see what happens. 

Blooms in outdoor water features


Reproduction – Having one is like having 100! 
Water hyacinth reproduce extremely quickly by putting out multiple shoots with new plants on them (plantlets).  They will stay attached for a while but when picked up or moved these easily break apart.  These new plants will follow suit and before you know it there are more hyacinth that you can imagine.

Luckily, they are annuals here in Colorado (Zone 5) which means they will not overwinter.  When there are too many, just throw them out! (Also great for the compost). Originally from South America, they are very sensitive to cold water. In southern states where the weather is much warmer they are even outlawed as even one plant let go in a natural waterway can overgrow to the point of needing to be removed! 

Hyacinth Reproduction
I started with two water hyacinths and this is a fraction of what I have now!


Here in our lovely zone 5 these plants provide excellent filtration.  Their roots hang down into the water, often growing down 12 inches long.  They consume the nutrients found in the water, removing it so that algae has less food. 

Water hyacinth roots - excellent filtration
This is a small hyacinth – their roots are a lovely purple-black and act as excellent filtration.


Great plant for hiding edges or softening rocks! Hyacinth can be placed on the edge of a pond and kept there by placing some rocks on top of the roots to anchor them in place. They can also be allowed to get stuck in the edges of waterfalls. If they don’t get stuck enough then may need some assistance.  Putting some rocks on the roots to help them stay in place will allow them to cascade down the waterfalls as they form new plantlets. 

Softening in outdoor water features

Fish Nutrition

Koi will eat the roots of water hyacinth!  I keep mine in the waterfall until I have a plethora of them.  Then I put some into the pond.  They provide first rate nutrition for the koi. 

What about when they float into the skimmer?

If you have given up on water hyacinth because they were floating into the skimmer, or you don’t want the fish eating them, try one of the following:

  • Tie them with fishing line to a rock so they can’t be swept into the skimmer.
  • Purchase a floating plant net that protects them from the fish eating the roots, allowing them to continue to provide filtration. This keeps them from getting caught in the skimmer.  You can easily use fishing line to tie them to a rock and it will hardly be visible.  (See picture below).
  • Put them in the waterfall.
  • Put them in the biofall.
Water hyacinth in plant protection net

Want to know more about the 5 Elements to a healthy Pond? Click HERE.

Need more information about pond algae? Click HERE.