All aquatic weed species have various tolerances to herbicides and chemicals so it it very important to know the weed name for good results with herbicide. KNOW YOUR WEED SPECIES THEN USE THE APPROPRIATE CHEMICAL HERBICIDE TO KILL IT. Diquat, as a general pond application, can be used for submerged weeds in shallow water less than 4 ft deep. For submerged weeds in water deeper than 4ft a subsurface application as injection (drop tubes) to the bottom area and drug through the weeds where they are rooted to the bottom is needed for effective results. As mentioned the chemical has to get to where it surrounds the weeds (in contact) so it is absorbed to kill the weeds.
Another option is to use an appropriate granular herbicide that sinks to the bottom, dissolves and releases the herbicide to be absorbed by the plants. Granular herbicides work well for spot treatments.
Last edited by Bill Cody; 03/20/18 03:10 PM.
