June 1, 2016

How to mow a lawn for healthier grass

By Erin Hynes
How to mow a lawn for healthier grass.
How to mow a lawn for healthier grass.

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.

If you're having problems with your mower, check out our troubleshooting advice and repair guides.

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 mowing 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:

Common bermuda grass    1 to 2 inches

Fescue 2 to 3.5 inches

Kentucky bluegrass 2 to 3.5 inches

St. Augustine 2 to 4 inches

Zoysia 0.5 to 1.5 inches

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 no longer lifts the grass well; it can also throw off the balance of the blade, causing the mower to vibrate.

Symptoms common to all riding mowers & tractors

Choose a symptom to see related riding mower and lawn tractor repairs.

Main causes: dead battery, stale fuel, bad starter solenoid, ignition system problem, bad ignition interlock switch, clogged carburetor
Main causes: damaged cutting blade, worn deck pulley, damaged mandrel pulley, loose fasteners on mower deck components
Main causes: shift lever needs adjustment, neutral control needs adjustment
Main causes: engine overfilled with oil, leaky head gasket or sump gasket, damaged carburetor seals, cracked fuel pump, broken fuel line
Main causes: punctured tire or inner tube, leaky valve stem, damaged wheel rim
Main causes: worn or broken ground drive belt, bad seat switch, transaxle freewheel control engaged, transaxle failure, dirty carburetor
Main causes: unlevel mower deck, dull or damaged cutting blades, worn mandrel pulleys, bent mower deck, engine needs tune up
Main causes: worn or broken blade belt, broken belt idler pulley, blade clutch cable failure, bad PTO switch, damaged mandrel pulleys
Main causes: clogged carburetor, damaged flywheel key, dirty spark plug, stale fuel, improper valve lash, engine needs a tune up

Repair guides common to all riding mowers & tractors

These step-by-step repair guides will help you safely fix what’s broken on your riding mower or lawn tractor.

How to replace the air filter on a riding lawn mower

Get your mower running smoothly again by replacing the air filter—it's a quick job you can do yourself, following these steps.

Repair difficulty
Time required
 15 minutes or less
How to replace the starter motor on a riding lawn mower

If you hear the solenoid click but don’t hear the starter motor spin when you turn the key, follow these steps to replace it.

Repair difficulty
Time required
 30 minutes or less
January 1, 2015
By Lyle Weischwill
How to replace a riding lawn mower blade

If a blade on your mower is dull or bent, replace it following the steps in this repair guide.

Repair difficulty
Time required
 30 minutes or less

Articles and videos common to all riding mowers & tractors

Use the advice and tips in these articles and videos to get the most out of your riding mower or lawn tractor.

May 1, 2017

Riding lawn mower engine spins but won't start video

By Sears PartsDirect staff

Troubleshoot fuel, spark and compression issues.

May 1, 2017

How to repair a riding lawn mower tire video

By Sears PartsDirect staff

Learn when you can use sealant to fix a flat tire.

June 1, 2016

How to mow a lawn for healthier grass

By Erin Hynes

How often and tall you mow your lawn has a big impact on its health. Check out these 3 rules.