can someone explain this? i have a customer, elderly lady, she needs to tell me exactly what to do. whatever, i crank her on the price, and do as she wishes (fert wise). ok, she gets 2 treatments a year, only in spring, she gets a fert and lime, that's it, nothing more for the year. exposure is full sun. she will not allow pesticides on the property, even for spraying the walkways, and i respect her choice. she pays extra for me to use a 21" mower, and cut it at 1.5" . now, she has no weeds. a little clover, but other than that, no crabgrass or broadleafs, and the rest somewhat healthy grass. this goes against everything we know....cutting at 1.5", no herbicides for years, not even enough fert to maintain a healthy lawn (roughly .80 lbs per k per season). why is her lawn NOT infested with weeds? or just plain dead?