Water hyacinth is a free-floating plant that produces a showy and very attractive blue/purple flower. As they bunch together and bloom, it provides a picturesque setting for any water garden. At least, that was the thought when these plants were given away to attendees of the 1884 World’s Fair in New Orleans, Louisiana. Some of these plants made their way back to Florida and found their way into the St. Johns River. Before long, the river was choked, river commerce nearly all stopped, and flooding began to occur. Water hyacinth continued to spread and eventually found themselves in almost every river, creek, canal, and lake in Florida.

History of Water Hyacinth

The Rivers and Harbors act of 1899 was a piece of federal legislation that tasked the U.S. Army Corps of Engineers to maintain open navigation through our national river systems – this naturally included water hyacinth management in Florida. Some of the best and brightest American engineers started developing dredges, conveyers, and harvesters to remove these plants. Thousands of tons of water hyacinth were removed each year, but since this invasive plant lacked any natural enemies to slow its growth and proliferation, it continued to spread despite these massive efforts.

It was not until the 1950s and the introduction of the herbicide 2,4-D that Florida started getting ahead of this floating menace. Herbicides were much cheaper than harvesting, allowing several hundred acres to be managed daily. This new tool, coupled with harvesters, could finally remove plants faster than the plants reproduce. The release of biological control insects further aided these techniques. These developments allowed Florida to keep this plant at bay with mechanical, biological, and chemical methods.

Is Water Hyacinth Still a Problem?

So, does this mean water hyacinth is a problem we have outgrown? Absolutely not! Although we now have more tools to manage this plant, water hyacinth has not changed since its introduction in the 1880s. The plant is still a super-aggressive invasive that loves to take over. If you let your guard down, it will make you regret it.

I hope this story serves as a reminder to all Floridians – please do not release non-native plants into the environment. These plants do not belong here and often cause many problems and should be considered a biological pollutant. Also, we need to remember that these plants, once released, do not become tame with time. They are destructive and expensive. The only way to keep our waterways open and clear is to manage them year-round and never expect them to play nice.

Learn more about Water Hyacinth

To learn more about water hyacinth, check out our podcast, “Working In The Weeds,” where we talk about all things aquatic and invasive plants. In our “Water Hyacinth Deep Dive” episode, we discuss this plant’s physiology, growth habits, reproduction, and how all of this comes together to make it one of the world’s most invasive plants.

For more on the history of water hyacinth, listen to our two-part mini-series “The Green Menace.” In these episodes, we will explore how water hyacinth entered Florida and the strides taken to manage this plant’s growth.

This blog post was written by Dr. Jason Ferrell, UF/IFAS CAIP director and professor. Questions or comments can be sent to the UF/IFAS CAIP communications manager at caip@ifas.ufl.edu. Follow UF/IFAS CAIP on Instagram, Facebook, and Twitter. Subscribe for more blogs like this one.

UF/IFAS Center for Aquatic and Invasive Plants. Turning Science Into Solutions.

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