The first step to this new paradigm is to raise the height of your mower. If you live in southern states, you'll want something around 2-1/2 inches high; in shadier northern states, 3-1/2 inches is recommended.
Taller grass has multiple benefits:
•The larger mass of grass blades makes the grass look greener overall, and problem spots will look less obvious than they did when you were mowing at putting-green heights.
•The extra green on top delivers more nutrients to the grass' roots and helps them grow deep, giving the grass better access to water and making it more drought-tolerant. Deeper roots also mean better access to soil nutrients.
•The thicker root mass and the taller green parts work to crowd out weeds by keeping weed seeds from germinating and crowding out any unwanted plant pests that do manage to germinate.
•Taller grass leaves help keep the sun off the soil, helping to preserve its water content.
•Your longer-cut lawn will require less mowing. (Cutting the grass short stimulates the plants to try to grow faster to make up for their lost greenery.)
While cutting higher is beneficial, certain fine-leafed grasses tend to fall over or get pushed down by the lawnmower, resulting in uneven cutting. If you're finding this is the case, try lowering the mower deck by a half-inch at a time until you find the preferred height. Alternately, mowing your lawn a little more often may also help allow you to maintain a tall "cut height" but still avoid the falling-over problem. If only a few problem areas suffer from falling-over grass blades, doing a second or third pass
over these areas can help touch them up. This usually works, especially when the additional passes are done at different angles.
Finally, most experts recommend not cutting off more than a third of your grass at any one time—doing so may stress the grass. So, if you're going for a cut height of 3-1/2 inches, you'd want to mow the lawn by the time it gets to about 5 inches tall.