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| HOME: MOWING |
Kentucky Bluegrass Perennial Ryegrass Tall Fescue Fine Fescues Other Grasses Seed Mixtures/Blends Site Preparation Sod Sources in Idaho Main Nutrients How Much to Apply When to Apply What Kind of Fertilizer How to Apply Mowing Height How Often Should I Mow? Clippings Mowers & Maintenance Type of Grass Time of Year/Weather Conditions Type of Soil Sprinkler Systems Billbugs White Grubs Earthworms Diseases Weeds Thatch Prevention Thatch Removal/Managment |
The simple, everyday task of mowing your yard is commonly overlooked in terms of its importance to the overall health of the lawn. If done correctly, mowing will not only make a lawn look nice, but will keep it healthy and more resistant to stress and invasion from weeds, insects and diseases.
Mowing Height Although there are differences in optimal mowing heights between the different types of grasses, for most home lawn situations, a mowing height of 3 inches is a good target to shoot for. Some grasses can tolerate lower mowing heights, such as perennial ryegrass and Kentucky bluegrass, but mowing too low decrease root growth and makes the lawn more susceptible to drought and heat stress as well as increase the incidence of weeds and diseases. Never mow your lawn lower than 2 inches.  Figure 1. Lower mowing heights require higher management inputs. Higher mowing heights encourage deeper roots. (Photo courtesy: A.J. Koski, Colorado State University) Some people recommend lowering the mowing height in the spring and again in the fall, but this is not absolutely necessary. It is more important to maintain the proper mowing height and to mow frequently so that you are not scalping the turf. Continue mowing late into the fall until the grass has stopped growing, sometimes as late as late November. This will remove excess debris and decrease the chance of snow mold. Raising the mowing height in the summer is a good practice. This higher mowing height, encourages deeper root growth and increases the lawn's resistance to drought stress. Even a 1/4 inch adjustment (one wheel notch on most rotary mowers) will make a big difference in the health of the grass. Check your owner's manual for the correct height setting or place the mower on a flat surface and use a short ruler to check the distance between the mower blade and the ground. BE SURE MOWER IS OFF AND DISCONNECT THE SPARK PLUG WHEN MAKING ANY ADJUSTMENTS AND WHEN CHECKING BLADE HEIGHT. How Often Should I Mow? The rule to use for determining how often to mow is the 1/3 rule which states: Never remove more than 1/3 of the leaf blades at any one mowing. So, if your mower is set at 3 inches, you should mow when your grass reaches 4.5 inches. Violating this rule not only scalps the grass and makes it look unsightly, but also buts the grass under stress. If you just can't seem to keep up with the growth of the grass, try raising the height a notch and slowly lowering over time to get back at the desired height. Clippings Contrary to popular belief, grass clippings are not a major contributor to thatch [hotlink]. Grass clippings are composed primarily of water and breakdown fairly rapidly in the soil. As long as you are following the 1/3-rule the clippings will not accumulate on the lawn and should filter back into the lawn. If you are not mowing frequently enough, large clumps of clippings on the surface should be removed because they will decompose slowly and may smother the grass. A hint in dealing with excess clippings is to let the clumps of grass dry for an hour or two and mow them again. This will help break up the clippings into smaller pieces and distribute them more evenly over the lawn. For additional information on grass clippings and their management see the University of Idaho's publication: Don't Bag It! You can download a PDF file at: www.info.ag.uidaho.edu/Resources/PDFs/CIS1016.pdf Mowers & Maintenance Rotary mowers are the most common mower for homeowners. It is important to keep the mower blade sharp so that the grass blades are cut cleanly. Too often this is overlooked, causing the blades to tear and rip instead. This leaves them open to diseases and stunts the grass. Sharpen the blade approximately every 4-6 weeks depending on the size of your lawn. If sharpening the blade yourself, use a file and follow the original bevel of the cutting edge, moving the file towards the cutting edge. Test the blade for balance by placing a screwdriver through the center hole and checking that the blade remains horizontal, if not, you may need to remove metal from the non-cutting edge of heavier side until balance is reached. Reel mowers are not as common and cut grass blades with a scissors-type action. These types of mowers are much more difficult to sharpen at home. Additionally, it is important that the stationary bedknife be properly adjusted to the cutting reel for a proper cut. Check with a hardware store or lawn mower mechanic for proper adjustment and sharpening of reel mowers. 
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