Aggressive Pond Weeds: Mosquito Fern

There are several pond weeds that are much more aggressive when certain conditions are present.  For example, mosquito fern, duckweed, and watermeal are extremely aggressive pond weeds that will blanket the pond surface if left unattended. 

Mosquito fern thrives in stagnant ponds that are rich in nutrients.  If your pond is surrounded by trees or gets very little wind action you may want to consider an aeration system to break tension on the water’s surface.  Also, reducing the amount of nutrients by using beneficial pond bacteria products may help slow down the aggressiveness of this pond weed. 

Once you start to see mosquito fern growing on your pond, immediate action is recommended.  Management options include physical control, biological control, and or chemical control.

• Physical Control: remove by raking the pond’s surface
• Biological Control: introduce grass carp or tilapia to help control the growth.  Keep in mind this method will not completely solve the problem.  Grass carp will consume mosquito fern, but it isn’t a preferred meal.  Tilapia can’t be introduced until water temps reach 55ºF and in most cases the plant has already advanced.
• Chemical: use of herbicides like Tsunami DQ is recommended.  Maximum dosages are required to keep control of an aggressive pond weed like mosquito fern.  The max dosage for Tsunami DQ is 2 gallons per surface acre.

For more information on controlling pond weeds contact the staff at Sanco.