If your lawn turns white after a mowing, it's time to sharpen your lawnmower blade. The white cast occurs when the blades of grass are torn rather than cut – the sign of a dull blade.
Mowing with a dull blade is like giving your lawn a bad haircut. Rather than cleanly cutting, a dull mower blade actually rips or tears grass blades.
This not only increases the intensity of the plant injury, but also the ragged edges serve as ideal entry points for various diseases.
Dull mowing is especially visible in hot weather when the tip of each grass blade dries out and turns brown.
Multiply this by several billion and your lawn may end up looking more like a field of straw rather than a lush green carpet.When mowing grass that is not met at the proper height,
a sharp blade ensures a clean cut that can seal quickly; which minimizes the potential for disease problems brought on by dull mowing.
So we prevent this by changing blades daily with sharp blades.