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A Word About Water Hyacinth

water hyacinchPatty here. Just about anyone with an ornamental pond has either heard of water hyacinth or has a personal experience with hyacinth to share.  I find it to be an interesting and useful plant, and here in PA we don’t have to worry about its invasive tendencies and notorious reputation like those of you in warmer climates.  I thought I’d give a little background on this floater to help you get to know it better.

Water Hyacinth Cross SectionWater Hyacinth (Eichhornia crassipes) is native to tropical South America where it forms vast mats on the water’s surface.  It is sun and heat loving and can reproduce at a ridiculous rate by producing long runners and stolons, which is why it is cosidered a noxious and invasive species in many states and countries.  They can double in population within about two weeks if the conditions are right!

hyacinth root structureIt has unique structure.  Each leaf has a spongy bulb which allows it to float on the surface, and the leaves have a waxy, waterproof feel.  The root system hangs in a long-stranded cluster beneath each plant, and the roots are white to dark purple-brown and very hairy.  These plants also produce beautiful flowers in the peak of summer, a cluster of light purple flowers with six petals each and a violet and yellow accent on the top petal of each flower.

Hyacinth does have its notorious side, and the reputation is well-deserved.  However, in cooler climates, and with responsible management this plant has carved out a valuable niche.  Because hyacinth grows and reproduces so rapidly, it makes a terrific solution to provide shade on ornamental ponds.  Two to three single plants is usually way more than enough to cover a broad area of water surface within a few short weeks, ad it will be necessary to prune the mat to keep the population in check.  The floating mat is a refuge for pond fish and frogs, a food source, and a form of natural, efficient biological filtration. 

The foliage and blossoms are as pretty as they are useful, but the roots are the real prize.  Not only do they provide a surface for fish to deposit eggs, but they serve as a safe haven for fry, tadpoles, and other organisms as they grow.   They have the ability to remove toxins, excess nutrients, and other compounds from the water and have even been used in industrial water treatment applications.  Hyacinth helps to oxygenate, and can even be placed in the filter’s sump as long as there is enough sun!

Hyacinth can be purchased for use in garden ponds in most aquatic garden and pond centers.  We sell it out of our retail location, but do not ship it. It is actually prohibited in many southern states.  If you choose to introduce hyacinth to your pond, don’t overdo it, purchase 2-3 plants, and see how they grow!  Provide them with plenty of sun, and protect the plants from your fish (who will think they are delicious) until they start to reproduce.  And as always, be careful and responsible if you need to dispose of extra hyacinth to ensure that they don’t find their way into natural ponds and waterways.


  1. avatar

    I have a reef tank and continue to have issues with my PH. I recently added calcium and I know it will lower the ph but I am having a hard time getting it back up to 8.3
    How high can I allow the alkalinity get before their is a problem. I know it reads high on my test kit. Do I have anything to worry about.

  2. avatar

    I need help with PH issues. I have a 125 reef and recently added calcium and now I cant get the ph above 8.0. I am worried about alkalinity level getting to high. Is their any danger in keeping adding buffer and having the alkalinity getting in the very high levels.

  3. avatar

    what are your current levels of calcium. mangnesium and alkalinity? Mag should be 1250-1350, calcium 350-450, and alk 8-12. Be sure to test pH at the same time each day as levels fluctuate. What buffer are you using? You may want to call or e-mail a marine biologist (cshank@thatpetplace.com) here so we can get the details we need to help solve the problem. There are many variables.

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