Mowing seems like such a simple task — just fire up the lawn mower, go back and forth across the whole yard, wait a week, and repeat. But improper mowing is the most common reason a lawn loses its good looks. Fortunately, encouraging a healthy lawn requires just three simple mowing practices.

Warning: Before working on your lawn mower, disconnect the spark plug (or remove the key if you have a battery-powered mower) so it can’t start accidentally.

Don’t Cut Off a Lot

Grass struggles to recover when you cut off more than a third of its height in a single mowing. That means if your grass is 3 inches tall, mow it to no shorter than 2 inches. A one-time, too-short mowing won’t do permanent damage, but repeated short mowings weaken the lawn, leaving room for weeds to invade.

For a few weeks in spring, when grass is growing fast, you might have to mow every 3 or 4 days. (If you hate mowing that often, skip the spring fertilizer treatment.) When growth slows in the heat of summer, you can get away with mowing only every 7 to 10 days.

Tip: An easy way to gauge how much to cut is to mow a swath about 4 feet long, then compare the height of the cut swath to the uncut grass beside it. Adjust the mower height accordingly.

Mow Tall

Tall grass shades the ground, reducing water evaporation from the soil and discouraging weeds. Keeping grass at the tall end of its recommended height range is especially important in the hottest, driest part of summer. In spring, you can keep it shorter if you like.

Ideal height depends on the grass type:

Grass species Height range
Common bermuda grass   1–2″
Kentucky bluegrass2–3.5″
St. Augustine2–4″

Use a Sharp Mower Blade

A dull mower blade frays the tips of the grass , which then turn brown and makes the lawn look dry. How often you need to sharpen the blade varies, but once a month is reasonable.  

Replace the blade every year or two, or anytime a rock or other hard object takes a big chunk out of the blade. Over time, sharpening removes enough of the blade that it now longer lifts the grass well; it can also throw off the balance of the blade, causing the mower to vibrate.