While fighting weeds is a year-round job, weed prevention is best practiced in the fall and early spring to take advantage of the growing season of turf grasses. A healthy, thick lawn is your number one defense against weeds. In fact, a badly weed-infested lawn is usually a sign of nutrient imbalance or other soil problems.
For a nice, green lawn that is free of weeds, focus first on getting your grass healthy, then give it a couple of months to become strong before applying weed control products. Minimize turf areas, so that you’re only growing grass where grass easily grows. A small patch of healthy grass is far more attractive than a huge expanse of thin, weedy lawn.
Small patches of weeds can be handled by pulling or digging. All-over lawn weed control is usually not necessary either, as a heavy infestation would be better handled by making the grass healthy. However, for those in-between situations, you may want to consider the use of a chemical or organic herbicide.