Scott Wahlin, CGCS said: This weed is at a cemetary in mostly St. Augustinegrass. There are drinking water wells there making this a zone 1 cone of influence. What would be the best choice of a herbicide in this situation?
That's a tough one then Scott...Not familiar with the zone 1 cone of influence, but I'm thinking that you are limited in regards to chemical treatment being standing water that an animal could drink from ect? However, Tower herbicide from BASF can be used as a pre emergent. Atrazine is a good post herbicide for St.Augustine, also Trimec.
But this weed is a sign of thin turf systemically caused by too little fertility and or too much water possibly. It has a dense root system and some what of a tap root too. Tough weed.
Hope that helps Scott