Grass that is cut properly will be healthier and more attractive. The goal of mowing is to keep grass long enough to absorb all essential nutrients and short enough to look good. It’s better to cut a little off each time (1/2-in. is best) and to mow more often. This encourages grass to grow fuller rather than taller.
Mowing at regular intervals will ensures that grass won’t grow too long or need to be cut too close. The rule is that the height of a lawn should be maintained between 1/2-in. to 1 1/4-in. high. It should never exceed 1 1/2-in. or less than 1/4in. To achieve this height, you will most likely need to mow once a week in the spring, fall and during summer dry periods and twice a week during prime summer growing periods. Cutting too much off at one time can shock the grass. If you must mow a overgrown lawn, first cut about 1/2-in. off the top. Then two days later, cut it once more to it’s usual height.
Credit: Renovate Your World