When you pull out the lawn mower for the first time this spring, take a few minutes to sharpen the blade for a cleaner cut. These sharpening tips from TruGreen will help you take care of the workhorse of lawn care:
- Drain the gas and disconnect the spark plug.
- Clamp a piece of wood to the deck to keep the blade from turning.
- Turn the blade bolt counter-clockwise to remove it. If there is resistance, apply some penetrating oil, wait 15 minutes, and try again.
- Remove the blade and mark the bottom side so you can put it back on correctly.
- Clamp the blade in a bench vise and sharpen with a 10-inch mill file.
- Use long strokes and work from the center outward.
- Use the same number of strokes on each side and keep the same angle.
- Balance the blade on a balance tool, an inexpensive pyramid-shaped tool found in most hardware stores.
- If one side of the blade hangs lower than the other, grind off excess metal from the end of the blade and not from the part just sharpened.
- Reinstall blade.
When you reinstall the mower blade, make sure you place it at the proper mowing height.
If you don’t have the time for sharpening, pack up your mower (or carefully remove the mower blade) and take it to a repair shop or home improvement store.
When you take your sharpened blade out for a spin, don’t get too enthusiastic. “Letting grass grow tall and then removing more than 1/3 of the leaf blade is called scalping and can damage the lawn,” said Ben Hamza, Ph.D., director of technical operations at TruGreen. “Be careful not to mow grass extremely low, as you can damage the lawn by cutting into the crowns of the plants.”
TruGreen professionals recommend that you measure the grass plants after mowing a very small area, then adjust your mower as necessary. Optimal mowing height varies by type of grass. Experts suggest the following mowing heights, in inches:
- Common Bermuda grass—1.0 to 1.5
- St. Augustine grass, Bahia grass—3.0 to 3.5
- Zoysia grass—1.0
- Rye grass, blue grass, fine fescue—2.5 to 3.0
- Tall fescues—2.5 to 3.0