I was talking with Alan Dennard who treats ponds in our area, and like myself, he claimed this season has been lowest calls for pond weeds in a while. We’ve had much fewer pond calls this year for some reason. But lately, I’ve been catching up. The good news is that we are moving back into a period better for treatment of pond weeds. If you treat on your own during the summer, we have to be careful not to cause an oxygen depletion which would kill fish. Treating 1/4 to 1/3 of the weed infestation at a time is recommended.
This week, I looked at a grass I had not seen before. It turned out to be baggy knee grass, one UGA Aquatic Specialist Dr. Gary Burtle says is showing up more and more in South GA ponds. The flower is easy to ID. To the left is a picture of that. The good news is glyphosate has activity on this weed. We pretty much start with this active ingredient for grasses nonetheless. A 2% solution spot spray with a surfactant is the recommended rate.
Behind you’ll also notice filamentous algae. There was also a submersed weed I could not see to identify. We’d have to use copper complex herbicides for algae and diquat for underwater weeds. With temperatures in the upper 80s and low 90s, we still have to take precaution in treating that algae and submersed weeds.