I had several stubborn weeds in my lawn, Oxalis weed which looks like 3 leaf shamrock clovers that sprout a yellow flower and Poa grass which people call crab grass. It took two separate trips for each weed type and they only charged me the initial charge as they advertise a one year warranty. I even offered to pay more but they wouldn't take it. Dave in the office is very professional and they definitely know their weeds. My lawn is flawless now with no weeds and bright green. I'd say 20% of my lawn was weeds prior this wasn't a simple task. Thank you