Today we go outside the house. If your beautiful green lawn takes on a white cast the day after you mow it, we've got a tip that will put a smile on your face. The white cast is nothing more than your lawn's torn blade tips drying out and losing their color. A lawnmower blade that is dull tears the grass instead of cutting it. Sharpen your lawnmower blade with a simple hand file and an oil stone. The sharper the blade is, the greener and more even your lawn will be when you're finished. With rotary mowers, be sure that you don't bend the blade while you're trying to sharpen it. If the two cutting surfaces are out of alignment with each other, tearing might result -- even if you've done a good job of sharpening.