Why are sharp blades Essential when mowing your lawn.
Having sharp blades on your mower is an important part of a healthy lawn. Think about the last time you cut a steak with a sharp knife compared to a dull knife. The sharp blade cuts cleaner, and easier.
When you have a clean cut on a grass blade, there is less surface area that needs to heal. This makes it easier for the lawn to recover after cutting. This also makes your lawn less prone to disease.
How often you should sharpen your blades depends on a number of factors including how long the grass is when your mowing, weather or not you have a lot of weeds, mulching vs. bagging, and weather conditions. Wet grass will dull a blade more quickly than dry grass.
A good general rule for the average homeowner is to sharpen your blades every 8 hours or once a month. However the more often the better. Get yourself a spare blade (or blades) that you can keep sharp on hand. That way you can just change it out, and take the dull blade to your local hardware store for sharpening.