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Alan Zuk

North Dakota State University

alan.zuk@ndsu.edu

Proper Mowing and Lawnmower

Maintenance

https://www.k-state.edu/wildcatway/nichols.html http://fohonline.com/newsroom/news/kansas-state-university-dances-with-

ashlys-ne80070pe-amplifier/

Sheep were often used to maintain turfgrass in rural areas through the 1920s.

http://www.antiquemystique.com/images/4277aa_jpg.jpg http://www.gravelyguy.com/lawnmowers-and-power-equipment.html

https://www.richardsonsaw.com/

Lawnmower Evolution

1920s-30s

1980s - Present1960s-70s

1940s-60s

https://picclick.com/Dear-Old-Dads-Vintage-Lawn-Boy-

Push-Mower-253918095335.html

Rotary mowers

Characteristics:

• Best used for turf to be maintained at a

height greater than 1 inch.

• Rotary mowers are easily serviced, and

are relatively inexpensive to maintain.

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Mowing

• Do a better job at cutting tall grass and seed

stalks than reel mowers.

• The blade tip speed on a 20 inch walk behind

rotary mower running at 3600 rpm is approx.

214 mph or 314 feet per second.

• Throw rocks and other items, can be dangerous

to bystanders.

http://www.four-h.purdue.edu/tractor/pictures/057.jpg

Sail

Rotary mower blade

Arm

Mowing

Rotary mower blade maintenance

•Sharpen blades after every eight hours of use

•Sharpen at a 30o angle•20o will cut but cutting edge will chip easily

•40o is too blunt

•Sharpen blade on top side only

•Attach blade to mower with sail positioned upward

•Discard blade when arm width wears down to one inch

Mowing

Dull mower blades cause:

•A reduction in turfgrass quality

•An increase in disease susceptibility

•A decrease in shoot density

•A decrease in water use rates

•A decrease mower fuel efficiency by 22%

Steinegger et al., 1983

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Mowing FrequencyOne-third rule:

A general rule of thumb for determining mowing frequency. Remove no more than 1/3 of the shoot height in one mowing.

Examples:

Mowing height Mow when Length removed

a) 1 inch 1.5 inch 0.5 inch

(1.5 x 0.3 = 0.5 inch; 1.5 - 0.5 = 1.0 inch)

b) 3 inches 4.5 inches 1.5 inches

(4.5 x 0.3 = 1.5 inches; 4.5 - 1.5 = 3.0 inches)

One-third rule:

• Do not remove more than 1/3 of the blade when mowing.

• Bagging is not necessary when following this rule.

• Grass clippings are comprised of 75-85% water and contribute

little to thatch if mowing is conducted with proper frequency.

• Clippings return the equivalent of 1 lb.

nitrogen per 1000 sq. ft. by the end of

the season.

Mowing Frequency

Mowing LowMowing High

Mowing Frequency

If you do would like to reduce your mowing frequency,

should you maintain a high or low-cut turf?

Assume that the canopy of turf (a) and (b) grows at an average rate of 1/4 inch per day and 1/3 of the blade is removed at each mowing.

If turf (a) is maintained at 1 inch, it would have to mowed after 2 full days of growth: 1” + 0.25” + 0.25” = 1.5”.

On the other hand, if turf (b) is maintained at 3 inches, it would have tobe mowed after 6 full days of growth: 3” + 0.25” + 0.25” + 0.25” + 0.25” + 0.25” + 0.25” = 4.5”.

Turf mowed higher is mowed less often! This is contrary to many

homeowners beliefs.

Mowing Frequency

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Mowing Height

Lowering the mowing height on a turf area results in:

• Reduced carbohydrate synthesis.

• Reduced leaf width.

• Reduced root growth rate and total root production.

• Reduced growth of lateral stems.

• Increased amount of chlorophyll per unit area.

Maximize rooting and lateral

spread by mowing high.

Be sure that the discharge chute faces out/away when mowing

around stationary objects.

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Also, be sure to discharge clippings away from unmowed grass

as you mow.

https://www.wikihow.com/Mow-a-Lawn

Is it okay to mow wet grass?

Soil Moisture and Compaction

Daniel, W.H. & R.P. Freeborg, 1979

http://www.brummellawn.com/category/lawn

Change mowing directions each time you mow to avoid rutting

your lawn.

• East to west

• North to south

• Lower right to upper left

• Lower left to upper right.

http://outdoorswithdave.com/landscaping/mowing-your-lawn

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Lawnmower rutting can even occur on dry soil if mowing

directions are not alternated.

https://wolberts.com/lawn-questions/lawn-ruts/

Heat tracking damage

https://www.canr.msu.edu/news/heat_tracking_damage_on_lawns

Tracking damage caused by mowing while the turf is subjected to heat and drought

stress.

Mowing on frosted grass

Tracking damage caused by mowing while frost on turf is visible.

https://www.customlawn.com/blog/how-to-make-lawn-mowing-patterns/

Lawn Patterns

Achieved by bending turf in opposite directions as you mow.

http://www.sportsfieldmanagementmagazine.com/article-1764.aspx

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http://www.usatoday.com/sports/baseball/stories/2001-06-27

-ballpark-designs.htm

Lawn Patterns

https://www.sporttechie.com/could-ruling-premier-league-change-major-league-

baseball-fields/

Intricate lawn patterns are created by brooming the turf.

https://www.scag.com/lawnstriping.html https://www.youtube.com/watch?v=YkjEPyVhxaA

Lawn Patterns

Lawn PatternsMow a straight line with your mower

Follow that line closely on the return pass

Mow twice if striping tall grass

…or attach a rubber mat to your mower for greater effect.

https://www.diynetwork.com/how-to/outdoors/landscaping/how-to-mow-designs-into-a-lawn

• Ryegrass is the most conducive turf for lawn patterns because of its shiny backside

• Other turf species can be striped too, especially if maintained at a short height

Fuel

Regular unleaded should be used in small engines.

Ethanol-based gasoline can be used unless the owners manual

instructs you not to.

Do not store your mower for long periods with ethanol-based

fuel in the tank. Ethanol will varnish the carburetor over time.

http://blog.autoparkchryslerjeep.com/does-ethanol-really-cause-damage-to-your-engine/

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Cleaner-5419-795066-796254-New/32770123206.html

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Air Filter Maintenance

• Wash sponge pre-cleaner with dish soap

and water.

• Wring out dry.

• Wrap in a cloth rag and repeat.

• Apply a coat of air filter oil.

• Do not use compressed air to clean

a paper filter.

• Tap paper element on the ground to

knock out dust.

• Apply a coat of air filter oil.

http://i.ehow.com/images/a04/8a/f0/clean-lawn-mower-spark-plug-800x800.jpg

Clean and gap spark plugs annually or as needed.

http://www.carpartkings.com/blog/2014/05/gapping-spark-plugs-efficient-firing.html