Answer: There is a fairly broad definition of what makes up a "lawn". (For instance, I remember my daughter having lots of fun blowing on dandelion puffballs in the lawn, but I do eradicate thistles.) In my experience, the absolutely "perfect" lawn is a lot of work! If you are truly intent on having a weed-free lawn quickly, and your lawn is currently predominently weeds, then you will probably need to use an herbicide such as glyphosate to kill the existing vegetation and start over from scratch and eventually achieve that picture perfect lawn. The other option is to accept a slightly less than perfect lawn and achieve it over time. You will encourage the lawn grasses and discourage the weeds through proper mowing (both height and frequency) and fertilizing combined with soil improvement based on the results of soil tests and perhaps spot applications of herbicides for truly pernicious weeds. You might also need to reseed in some areas where the lawn is the worst. You can learn more about the basics of good lawn maintenance (and establishing new lawns) in "Lawn Care for Dummies" by Lance Walheim ISBN 0-7645-5077-2. Your County Extension should be able to help you with soil tests and interpreting the results and may also have some localized lawn care information available.
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