Updated

Here are two simple ways to kill lawn weeds without herbicides:

• Sharpen your mower blades
• Raise the cutting height of your mower

Herbicides are the most commonly used pesticides on U.S. lawns. But you can literally cut them out — or at least cut them way down — by adjusting your mowing practices to favor the grass instead of the weeds.

Thriving grass = fewer weeds = fewer herbicides = less chance to harm your family, pets, and the environment.

Just follow these three easy steps and watch your grass grow healthier:

Step 1: Sharpen your mower blades.

How:

• Almost any repair shop will sharpen your blades for about $3 to $6. If they’re not badly nicked you can do it yourself.

• Tip: Buy an extra blade so you always have a spare sharp blade.

When:

• Once a month is ideal. But if you hit a rock, sharpen or switch blades ASAP.

Why:

• Dull mower blades tear the grass, leaving ragged tips on grass that turn brown. Damaged grass plants need more water and are more vulnerable to disease.
• Mowers with sharp blades burn 25 percent less gas.

Step 2: Raise your mowing height.

How:

• It’s easy to adjust the height of most mowers. Set the blade 3 to 3 1/2 inches above the ground — usually the highest setting.
• If you can’t do it yourself, ask a professional.

When:

• Next time you mow — and you’re done. You only need to change it once!

Why:

• Taller grass shades out and competes better with weeds.
• Taller grass plants send roots deeper into the soil, helping them weather drought.

Step 3: Sit back and watch the grass grow!

Learn more:

Lawn Care without pesticides
A 24-page book that covers all the basics. Get a free soft copy or order a hard copy for $10. Great Father’s Day gift!

Click here to get a free soft copy

• For a hard copy: send check or money order for $10, payable to Cornell University, to: Michele Kaufman, NYS IPM Program, 630 W. North St., Geneva, NY 14456. Put "Lawn Care" in the memo line of your check.

Integrated Pest Management

For more important lawn tips log onto Cornell University’s gardening website.

How to sharpen your mower blade:

• To avoid spills, sharpen your mower when the gas tank is empty.
• Wear heavy gloves and safety glasses.
• Remove the spark plug wire, and then remove the blade.
• Run a metal file down the cutting edge or use a cordless drill with a small grinding stone attachment. A vise makes this step easier.
• Check the blade’s balance so it will spin true. A balanced blade stays level when suspended from a screwdriver inserted through its center hole. Restore balance by removing some metal from the heavy end of the blade.
• Place the blade back on the mower and replace the spark plug wire.
• Next time you mow, you’ll see the difference — grass tips will look clipped, not torn. It may take several mowings to eliminate all the torn tips.