All About Mowing Part 3

Grass Clippings

Pick up or leave on the lawn?

 

I can't recall the last time I picked up my grass clippings. Its been years. It is extra work and in my case, with my cutting routine, my mower, grass types and soil conditions, it is quite unnecessary.  But it may not be unnecessary for you at the moment. Lets go over the finer points.

Grass clippings are almost 80% water. 10% is fiber or organic matter (good for soil) and what is left over are nutrients, similar to what you get in fertilizer, with perhaps some extra extra nutrients obtained right from the soil and air. Whenever you remove clippings you are disrupting the natural growth/decomposition cycle and are removing nutrients.  If these nutrients are not replaced by fertilizers, the grass will definitely deteriorate.  Most lawn experts agree that the fertilizer value of leaving your clipping will be roughly equivalent to one good feeding.

 

Here are 3 things to consider in regard to clippings:

1. Clippings must be short enough so they do not mat down on top of the lawn. They should filter down to the soil level and quickly decompose. If you cut often, especially on higher mowed lawns,  the clippings will be short and will drop down easily.  If you have a side chute discharge on your mower and find that the clippings remain on top and are unsightly, you can quickly go over the lawn again, just to cut up and disperse the clippings more.  Better yet, get a mulching mower which will chop the clippings up finely and throw them to the ground. A mulching blade may be available for your current mower. It chops the grass up more, but doesn't do the job a mulching mower can do.

1. On poor soils that are not bio-active, clippings may be slow to decompose. This may be the result of just having a dense clay instead of real topsoil. Or, it could be that there have been too many detrimental products put on the soil over the years, resulting in the kill-off or suppression of the beneficial soil microbes and earthworms that do the actual decomposing of the grass clippings.  Some fertilizers and pesticides and even excessive lime can have harmful effects on the bio-life in the soil. We'll cover all of this and teach you how to restore or create bio-life in your soil later on. it is one of my favorite subjects and the reason we started selling products on our website. 

1. Thatch. Grass clippings do not cause thatch unless they mat up without decomposing. In fact, most of the thatch problems I have seen over the years were on lawns where clippings were actually bagged!  How is that possible, you ask?   Thatch is actually is a matted, woven layer of grass stems, roots, runners, and clippings, that sits on top of the soil.  (Click here to see a nice photo of thatch on our website.)  Clippings add to the thatch, but don't necessarily cause it. Over-fertilized lawns, of course, make for more or longer clippings. If the soil is also not bio-active you have a real problem. Thatch and how to correct it will be covered as its own topic later in the manual.  If you find a thatch layer sitting on top of the soil, bag your clippings until it is corrected.

If you can do what is necessary to be able to recycle your grass clippings on the lawn, it will be well worth in many ways. If you really do need to bag the clippings, you can still use them for composting or mulching your garden beds. It would be a shame to see them going to waste.

In the next section we'll go over how to do the actual mowing of the lawn, all the little steps and nuances that will teach you to mow like a pro.

 

 

Stuart Franklin is president of Nature's Lawn & Garden, Inc and author of the book Building A Healthy Lawn: A Safe and Natural Approach.  Copies of the book are available though our office.