Sometimes in neglected yards, the issue is not the grass height. Instead, the species distribution is the problem. Wild broadleaf herbs and turfgrass often stand out on a shabby lawn - doubly so if it has been damaged or disturbed.  There are two ways to solve this problem without damaging your turfgrass. Pull the weeds manually, or use a broadleaf herbicide product that affects only the plants with - you’ve guessed it - broad leaves. Note that manual pulling is a much healthier option for the property owner and the environment - although it can get costly if you don’t do it yourself.