Mowers And Mowing: Don't Bag It - The Lawn Maintenance Plan

John R. Street
William E. Pound

Lawn mowing requires more time than all other operations involved inmaintaining a high-quality lawn. Bagging and removing grass clippingsjust adds to the time and drudgery involved in the mowing operation.It must be clearly understood that improper mowing can have damagingeffects on both the health and quality of the lawn. It can also bevery detrimental to the success and homeowner acceptance of the Don'tBag It program. The two most important aspects of mowing are propermowing height and proper mowing frequency.

Mowing Height

Selecting the correct mowing height dependsprimarily upon the species of grass in the lawn. The appropriatecutting heights for the common lawn grasses found in Ohio are listedin Table 1.

Lawn grasses, like most other plants, must manufacture food throughthe process of photosynthesis if they are to survive and grow. Thisprocess occurs mainly in the leaves of the plant. Typically, the moreleaf area, the more food produced. Grasses cut at low mowing heightscannot sustain the rate of photosynthesis necessary to produce enoughfood to maintain a healthy plant because of a low leaf area. Theshort mowing height weakens the grass and increases itssusceptibility to weed invasion, disease and injury from drought andsummer heat. Higher mowing heights favor deeper grass roots, agreater number of roots and an overall healthier grass plant. Thedeeper, more prolific root system increases the capability of thegrass to acquire soil water and nutrients. This, in turn, makes lawnmaintenance easier.

It is advisable to raise the cutting height of the lawn slightly (by1/2" plus) in the summer to provide more shade to the lower portionof the grass plant and soil to reduce heat stress and, also, toincrease the leaf area available for food production.

Mowing Frequency

Mowing frequency is extremely important inthe Don't Bag It program to ensure a healthy lawn and reduce theaccumulation of clipping debris on the lawn surface.

The homeowner should never remove more than one-third of the totalleaf surface at any one mowing. For example, if the selected mowingheight is two inches, the grass should not grow to more than threeinches before it is mowed.

Removing more than one-third of the leaf surface at one time resultsin an open, stemmy appearance of the lawn, weakens the grass plant,reduces or stops root growth, and leaves significant clipping debrison the lawn surface. Clipping debris is not only unsightly as itdries on the lawn surface, but it also excludes light from the grass,further reducing its health. Mowing will normally be required moreoften in the spring and fall with a frequency of at least once everyweek.

Other Mowing Considerations

Mow lawns when dry so clippingswill not clump together on the surface of the lawn.

There will be periods of time in which prolonged rain makes itimpossible to mow grass regularly. The longer clippings resultingfrom an infrequent mowing can still remain on the lawn if the clumpsof grass are spread out evenly over the lawn to allow them to readilydecompose, or if the clippings are allowed to dry for a day or two,then mowed again to distribute them evenly.

If for any reason the quantity of clippings is too great to leave onthe lawn, remove and distribute them around trees and shrubs as amulch. Grass clippings can also be composted.

Mowers

Any lawn mower can be used to return grass clippingsto the lawn. Rear-bagging mowers normally have a discharge door thatcan be closed when the bag is not in use to eliminate clippings andother debris from flying at the operator. Also available areaccessory attachments for most mowers to seal off or close thedischarge openings or ports. Side discharge mowers can simply returnclippings by leaving the port open. Check with your local dealer.

Mulching mowers are designed to recycle (recut) clippings underneaththe mower housing resulting in clippings being cut into smallerpieces. These smaller pieces sift down into the lawn more readilythan non-mulching mowers and reduce clipping debris on the lawnsurface.

The Don't Bag It lawn care plan can save the homeowner time, energyand money, and reduce the amount of waste going to our landfills. Theprinciple is simple - return clippings to your lawn. By leaving yourclippings on the lawn and allowing them to work their way back intosoil, you can realize these benefits and still maintain a beautiful,green lawn.

In fact, grass clippings contain valuable nutrients that can generateup to 25 percent of your lawn's total fertilizer needs. A hundredpounds of grass clippings can generate and recycle as much as threeto four pounds of nitrogen, one-half to one pound of phosphorus, andtwo to three pounds of potassium back to the lawn. These are thethree most important nutrients needed by lawns and commonly suppliedin lawn fertilizers. The other good news is that grass clippings donot contribute to thatch (an organic debris layer between the soiland live grass) since grass clippings are 75-85 percent water anddecompose readily.

Why, then, do many homeowners bag grass clippings? Basically, it is apersonal preference and habit most homeowners have acquired. Anotherreason is that bagging does ensure that no clippings remain on thelawn to detract from lawn quality and aesthetics. Proper lawn carepractices will usually eliminate surface clipping debris and ensure asuccessful Don't Bag It program.

Rule of Thumb

Frequent mowing is the key to the success ofthe Don't Bag It program - never remove more than one-third of theleaf surface at any one time.

Mow lawn grasses high and raise the cuttingheight slightly in the summer.