Raise the mower blade an inch or more in areas where excessive shade is present. A Sharp Blade is Essential Most lawns are mowed with rotary mowers, which cut by impact. The blade must therefore be sharp so that the grass leaves are cut smoothly. A dull blade shreds the grass and causes splitting of the leaves, allowing fungus diseases many entry points. Check the mower blade for sharpness before each mowing and learn how often it should be sharpened during the season.
Some gardeners routinely sharpen the blade after each third mowing.
Moisture Levels at Mowing Grass should not be mowed when the leaves and stems are wet. In addition to less efficient cutting, there is at least one disease that can be spread when mowing a wet lawn. Though the stems and leaves should be dry, grass should not be mowed if soil moisture is low. Avoid mowing wilted grass. It is better to delay until sufficient irrigation can be applied.