Contacts
 




Keyword Site Search










Catching Vs. Thatching






Turf should be mowed often enough that no more than 1/3 of the length of the grass blade is cut in any one mowing. If this is performed properly, mower clippings begin to break down quickly, releasing the water and nutrients contained in the tissue, therefore preventing thatch buildup.


As your crew mows acres and acres of landscape, you generate a great deal of clippings. What to do with this byproduct of mowing is a problem faced by all landscape superintendents. While bagging may be the simplest option, it adds to your costs and can waste your crew's valuable time. The other option is thatching or "grasscycling," which is the process of leaving a layer of clippings on the turf after mowing that then help fertilize the landscape. However, too much thatch can be detrimental to the grass it is meant to fertilize.

Grasscycling

By returning lawn clippings to the soil rather than bagging and disposing of them, you are helping reduce the solid wastes going to landfills. Properly done it encourages a healthier grass stand, and with no need to remove, bag or haul clippings, it saves your crew time and energy. Grass clippings begin to break down quickly after mowing, releasing the water and nutrients contained in the tissue. The decomposing clippings release nutrients to the soil and may enhance soil microbial activity. The need for nitrogen fertilizer can also be reduced by 20-30 percent, due to nitrogen returned to the soil from decomposing clippings, therefore saving you money.

Mowing Height

Improper mowing can have damaging effects on both the health and quality of the lawn, which can make the question of catching versus thatching moot. The two most important aspects of mowing are proper mowing height and proper mowing frequency. Selecting the correct mowing height depends primarily upon the species of grass in the lawn. The appropriate cutting heights are listed to the right.

Lawn grasses, like most other plants, must manufacture food through the process of photosynthesis if they are to survive and grow. This process occurs mainly in the leaves of the plant. Typically, the more leaf area, the more food produced. Grasses cut at low mowing heights cannot sustain the rate of photosynthesis necessary to produce enough food to maintain a healthy plant because of a low leaf area. The short mowing height weakens the grass and increases its susceptibility to weed invasion, disease and injury from drought and summer heat. Higher mowing heights favor deeper grass roots, a greater number of roots and an overall healthier grass plant. The deeper, more prolific root system increases the capability of the grass to acquire soil water and nutrients. This, in turn, makes lawn maintenance easier.

It is advisable to raise the cutting height of the lawn slightly (by 1/2” plus) in the summer to provide more shade to the lower portion of the grass plant and soil to reduce heat stress and, also to increase the leaf area available for food production.








The "1/3 Rule"

Turf should be mowed often enough that no more than 1/3 of the length of the grass blade is cut in any one mowing. Using the rule, the short clippings will fall through the canopy to decompose and will not cover the lawn surface. Done properly, this will not contribute to a thatch buildup.

Catching

If you do bag your turf clippings, instead of simply disposing of the waste, you can use it as mulch for gardens or landscape beds. Be careful when placing the clippings around tender young plants -- the clippings can heat up as they decompose, and this may injure young transplants. Also, refrain from using clippings for mulch that were recently treated with weed control products (herbicides). Research indicates that the herbicide can volatilize from clippings and injure sensitive plants such as annual flowers. Allow at least two weeks after application of weed control products before using treated clippings as mulch.

Composting Clippings

Grass clippings make an outstanding contribution to compost piles because of their high nutrient content. Efficient composting is accomplished by layering green material such as grass clippings, weeds or kitchen scraps with brown materials such as leaves and soil. The compost is a valuable resource for landscape and garden beds as a soil amendment or mulch.






Do not use turf clippings for mulch that were recently treated with weed control products. Research indicates that the herbicide can injure sensitive plants such as annual flowers. Allow at least two weeks after application of weed control products before using treated clippings as mulch. Photo: kubota tractor corporation.


Tree Leaves

Researchers have found that mowing fallen leaves back into turf is an appropriate alternative to bagging. Reports from turf managers who have been practicing this technique on golf courses and commercial turf have been positive. The leaf residue will be evident after mowing, but it will sift into the turf within a few weeks and will be unnoticeable in the spring.

Too Much Thatch?

Returning clippings to the lawn will not normally harm the grass plants or contribute to thatch buildup. Thatch is the accumulation of dead and decomposing turf stems, leaves and roots intermixed with live plant roots and soil that occurs at the soil surface. It can be viewed by cutting downward into the lawn, peeling the sodback and examining the cut piece from the side. A thatch layer of approximately 1/2 inch is beneficial because it acts as a buffer at the soil surface and protects the plants from extreme weather.

Thatch that builds up over 1 inch, however, can inhibit water and air movement and weakens the turf stand. Excessive grass clippings left in piles on the lawn surface will smother and severely injure the turf. If you have a thatch layer of 1 inch or more, you may want to consider a core cultivation of your turf to alleviate the thatch.

Compiled from: ucce.ucdavis.edu, ohioline.osu.edu, turf.msu.edu.



Related Stories




October 13, 2019, 6:45 pm PDT

Website problems, report a bug.
Copyright © 2019 Landscape Communications Inc.
Privacy Policy