Hydrilla verticillata was introduced to the United States in the 1950s and it has now spread to nearly 30 states.  It is particularly bad in the southeastern states like Georgia and Florida, as well as other warm climates like Texas.  This is peak season for Hydrilla in many areas of the country!

Hydrilla management may require a series of applications using several solutions.  Here are some tips on controlling what some people call “the worst weed in the world.”

Why Hydrilla management matters

Hydrilla is not just ugly to look at. It is a serious threat to water quality and safety.  Hydrilla can choke waterways, impeding recreational activities such as fishing.  It can also clog water structures and intakes, causing expensive damage.  While hydrilla management can be pricey, failing to manage it can be even more costly.  Take, for example, the situation in Ithaca, New York, where local authorities have spent nearly a million dollars to manage hydrilla.

Determining your Hydrilla management plan

Knowing your strategy can help you determine a course of action. The big question is whether you want to take a short-term approach (knock the weeds down ASAP) or a long-term approach (manage now and eradicate for good). You can control it over a few months, but getting rid of Hydrilla completely takes consistent management.

Once you have set a goal, you can decide which solutions will help you meet it. Of the SePRO Hydrilla management products available, the most prominent technology is Sonar® – particularly the pellet products such as SonarOne.  Those are advantageous because the formulations maintain a low concentration of Sonar in the plant zone over an extended period of time.  This low concentration controls the weed and the tubers that are sprouting.  Those tubers can live for as long as 10 years or more – which is why this plant is so difficult to control!

Tips for applying Hydrilla management products

Here are a few tips on getting the best results:

• Start early in the spring at the onset of growth when the plants are small (less than 12 inches).
• Reapply as needed to maintain the concentration level for 60 - 90 days. The ideal number of applications depends on water flow and its impact on dilution.  If you’re concerned about precision, you can use the FasTEST® assay to measure concentration of Sonar in the water.

Whether your hydrilla infestation is a new problem or an ongoing problem, the key is to act quickly and treat consistently.