Tip 1: Adjust your cutting height to the time of year (and use a sharp blade)
For cool-climate grasses, use a 1-1/2 in. cutting height for the first mowing of the year to remove dead grass and allow more sunlight to reach the crowns of the grass plants. Raise the blade during the heat of summer to 2 or more inches. Then lower the blade back to 1-1/2 in. for the last cutting of the year. For warm-climate grasses, these heights will be about 1/2 in. lower.
When adjusting your blade height, measure from a hard surface to the bottom of the mower deck, then add 1/4 in. (most blades sit 1/4 in. above the bottom of the deck).
Cut your grass using a sharp blade (illustration below). A dull one tears grass rather than cutting it cleanly. Damaged grass turns yellow, requires more water and nutrients to recover, and is more susceptible to disease. Sharpening and balancing a blade three times a year is usually enough to maintain a good cutting edge— unless you hit lots of rocks.
Use a Sharp Mower Blade
A well-maintained (sharp and balanced) blade cuts grass cleanly and evenly.
A poorly maintained (dull) blade shreds grass, leaving it more susceptible to disease and in need of more nutrients to repair the damage. An unbalanced blade compounds the problem (and can damage your lawn mower’s bearings).