At our old house we had our lawns treated regularly by Green Thumb. This is a franchise business. For several years and with very little effort on my part (apart from mowing) the grass was very green and totally weed free.
Last week they gave the first treatment to the lawns at our bungalow. Already, the weeds are dying, so the signs are promising. These days there are similar companies fighting for the lawn care business. I have only experience of Green Thumb, who are good. I could probably do the same lawn care treatments myself, but not sure the results would be as good. It is surprising how many people asked me how I managed to keep the lawns looking so good. I just tell them Green Thumb!