If you have a lawn -- and most people do -- it makes sense (in parts of the country where lawns are environmentally OK) to take care of it.
The easiest way to do that is to mow it correctly. Tests have shown that mowing your grass high decreases weeds (a thick turf crowds out weeds and new seeds don't germinate when shaded) and water use (deeper roots are able to withstand lack of water for longer periods of time and soil stays more moist when it's not exposed to the sun).
There are also other benefits.
Yet, I'm always amazed at how people resist this simple change that can make their lives easier (they mow less often) and make their lawn look better.
If you have fescue, bluegrass, or other cool-season grasses in your yard, you want to keep it about 3 inches high.
According to the "one-third rule" of mowing -- which says that you shouldn't remove more than one-third of the blade at a time (otherwise, you shorten and weaken the root system on which your grass depends) -- that means waiting to mow until the grass reaches 4 inches tall.
For warm-season grasses, the mowing height and target height can vary, so check with your local Cooperative Extension Service office for specific heights. Generally it will be 2-1/2 inches.
Of course, waiting till the grass reaches a certain height before mowing means that you can't just plan to cut your grass every Saturday. In spring you might mow every five days and in August, every two weeks. (And if you mow less, you'll be saving high-priced gasoline.)
If your yard is weedy, the first month of mowing it higher will see an uneven lawn -- as the weeds may reach higher than the grass. But persist and you'll be delightfully surprised at the positive difference this one change can make in your lawn.