A sharp tool cuts the plants evenly, while the blunted blade leaves a fringe. If the blade is good-sharpened, the grass is cut neatly and evenly, and the next day the cut is tightened. Such a lawn looks attractive and bright.
When the blades need to be replaced, it damages the plants. It looks like the top of the grass was cut into several parts. For example, this happens if you tear the grass with your hands. Also, in this case, your lawn obtains a dirty-green color. When the blade becomes dull, bent, or deformed, the lawn looks untidy after the mowing.
The blades must be sharpened or replaced when they become blunted. This can be determined by the grass after mowing the lawn. If the tips of the grass begin to turn yellow and have a non-standard fiber structure, it is time to replace the blades.