For northern lawns you will want to apply 2oz of weed b gon max per gallon of water. If using the product on a southern lawn use 1oz of weed b gon max per gallon of water.
Weed B Gon MAX Kills acticly growing weeds. It is systemic which means it works through both the foliage of the weed you are tying to kill as well as the roots. Generally twisting and discoloration...
Regular Weed B Gon MAX will not kill watergrass. If you use Weed B Gon MAX Plus Crabgrass Killer for Lawns (int he ready to use version) it will kill watergrass.