Eurasian Watermilfoil (Myriophyllum spicatum) is an exotic species
most likely introduced in the United Sates by the
aquarium industry. EWM grows densely and creates a canopy of vegetation
that blocks out sunlight suppressing our native plants. EWM can grow
to nuisance levels in lake areas previously devoid of such problematic
growth compounding its impact.
Q. What are the best control options?
A. Herbicide Application:
Herbicide control of EWM is a slam-dunk – EWM is susceptible
to a hand full of herbicides. Large-scale treatments must consider
many factors, contact us directly when considering whole lake applications.
Below are common scenarios that face the typical lakeshore or pond
Which one when?
- Big Problem:
herbicide – If EWM is your big problem
this is the herbicide of choice.
It just plain works and kills the
root structure. Note: Navigate
will control lily plants. If many weed types are
present that require control a
broader spectrum herbicide may
be a better choice.
- Mixed Submerged Weeds:
191 granular and Reward
liquid or Aquathol
Super K Granular are also effective EWM control agents.
All three are very broad-spectrum. If you have
a mix of submerged weeds these offer a good alternative
to Navigate. The term of control may not be
as long as Navigate but all offer good relief.
- Whole Pond Treatment:
herbicide is another great choice but is not effective in
a small control site due to its long contact time requirement.
However, for a whole pond treatment it is our
It is hard to recommend cutting
or raking when it comes to EWM. The plant easily
regrows by fragmentation facilitating its spread.
Herbicides work great, reach places that cutters/rakes
cannot and last much longer. If the lake already
has EWM throughout then physical maintenance
in conjunction with herbicide control is helpful.
Q. When is the best time to treat?
A. Once water temperatures are around sixty degrees or warmer and
the plants are viable.
Unfortunately, EWM arrives sooner in the spring and stays longer than our native
plants thus the control window is longer.
Q. How do I actually apply the product(s)?
A. Granular herbicides can be spread by a small Hand
held spreader or can be tossed by a hand scoop. Liquid herbicides
should be applied by a hand held pump up type sprayer or a Solo
Back pack sprayer.
Q. How often do I need to treat?
A. This varies with EWM depending upon adjacent influences and control
products. On average, two applications per season. Your treatment site
results will establish there own history and hence the future predictability.
Keeping good records of your application will expedite any tailoring
that need to be done. Remember, we are here help!
Q. How long before I see results?
A. Generally within ten to sixteen days things will be cleared up.
recommended products online:
- Reward liquid
Super K Granular
- Sonar herbicide
Back pack sprayers