Going Green: How to have a Green-er Lawn

 

Going “Green”:  How to have a “Green”-er Lawn August 2008
 
Jon Jackson, President
Global Neighbor, Inc
www.g-neighbor.com
Sabina Mueller Sulgrove, Ph.D.
Botanist and Horticulturist

The EPA estimates that only 35 percent of lawn fertilizers ever reach the grass plant (Joe Lamp’l, The Green Gardener’s Guide, 2008).  The remainder is volatized into the air or seeps into groundwater.  The fertilizers, herbicides, pesticides and other -icides that are used on lawns can have far-reaching effects.  Most herbicides, even though they are water soluble, can remain in the soils for a long time.  At high levels these chemicals may be toxic and can cause cancer, negatively affect the nervous system, and create reproductive difficulties (US News and World Report, May 5, 2005). The EPA’s website, www.epa.gov/OGWDW/contaminants/index.html#organic lists major pollutants of ground water and their health effects.

How can we still have a lawn that is the envy of the neighborhood without harming the environment? Here are some simple steps that we can take.

1. Use Core Aeration to Improve the Soil

Jeff Lowenfels and Wayne Lewis (Teaming with Microbes, 2006) give a simple way to measure the composition of your soil.  Use a clear quart container and add 2 cups of water and a tablespoon of Calgon water softener.  Dig a sample of soil from your garden by using a bulb planter to remove a core of soil.  Add it to the quart container; shake and let it sit until the soil settles into layers, usually 1-2 days.  Then measure the thickness of each of the 3 distinct layers: sand on the bottom, silt next; and then clay, the smallest-sized soil particles is topmost, with liquid on top and the organic matter floating on the surface.  A good soil has 30-50% sand, 30-50% silt, 20-30% clay and 5-10% organic material.   What is your soil lacking?  It’s likely that there is very little organic matter in your soil because most lawns are developed on subsoil after the builder has removed topsoil.

Now you that you know what’s in -- or not in -- your soil, let’s fix it.

Use core aeration http://www.ext.vt.edu/pubs/turf/430-002/430-002.html to improve compacted soils and improve the texture of your lawn by introducing air cores into the soil.  Plant roots need oxygen to grow well.  A special machine The Lesco Aerator – Pull Type is used to remove 1 to 6-inch long plugs (depending on the equipment), which then are spread on the lawn surface.  Run your core-aerating machine twice, the second time at right angles to the first path.  This double aeration pattern creates a higher density of cores than a single pass.  Add compost or the other soil amendments that are needed to improve your soil by pouring them onto the grass and raking it over the open cores.  Aerating the soil along with the adding amendments improves the soil texture and adds nutrients.

2. Fertilizing the Lawn
In the spring apply an organic fertilizer to the lawn surface. Use corn gluten, a by-product in the production of cornstarch and corn meal, and alfalfa-based fertilizer in the fall. These organic fertilizers slowly release nutrients as they decompose. Because these nutrients are associated with decomposed matter and thus release nutrients slowly, they do not threaten surrounding wildlife or children or burn your lawn in drier months.

3. Make Your Own Compost/Organic Fertilizer

For the long term, make your own organic fertilizer by starting a compost pile or use a composting bin. Put into a pile small twigs pencil thickness or less, pine needles and Christmas tree branches, grass clippings, leaves, dried tops of perennials that you cut back in the fall, and weeds – and the accompanying soil – as well as grass clumps removed when edging flower beds and walkways.  These organic (once living) materials decompose with time into humus, which is a nutrient-rich soil composed of particles of different sizes that allow for both air, water, and dissolved nutrients to move freely through it.  A compost pile needs a variety of plant materials in it -- along with soil, which provides the microbes that decompose the plant materials. 

There is no one-way, right or wrong way to make a garden compost pile.  You can just pile the plant materials in a heap, or run them first through a chipper, along with twigs and branches. You can turn a pile weekly with a pitchfork for faster decomposition, or you can simply let it sit for several years, and then harvest your “green gold” from the bottom of the pile.

By composting your garden wastes rather than putting them out to the curb in the trash, you are recycling the dead plant materials into nutrient-rich compost to reuse in the garden.  If necessary you can sift the compost through a ½-inch wire mesh to remove stones, large pieces of wood, old plant labels, plastic bag pieces, or anything else that fell into your compost pile and did not disintegrate. 

Compost differs from chemical fertilizers in that the dissolved nutrients adhere to soil particles that help improve the soil’s capacity for improving drainage and air-holding capacity.  The nutrients that have been released during decomposition of plant materials are reduced to the same chemical form as chemical fertilizers.  Plants can only absorb nutrients in a simple form, and that form is identical whether from chemical fertilizers or from organic materials (compost).  But organic fertilizers from compost provide the added benefit of its association with soil particles that can improve the texture or the garden soil to which it is applied.

Compost can be used in the garden in a number of ways. 
· Use a thin layer of compost to top-dress/fertilize your lawn.  The compost also evens out the lawn surface.  Compost can be spread in the bare areas of the lawn before reseeding.
· When transplanting annuals, perennials, or vegetables to the garden dig a hole in the soil, add compost and then add the transplant, fill compost around the plant, and finish off with a top layer of some of the native soil.
· Add compost as a fertilizer around your garden plants in the spring, and lightly scratch it in. around the plant.
Compost can also be used to make a new flowerbed.

4. Weed Control in Your Lawn

The best way to prevent weeds is to have a vibrant and healthy lawn.  A healthy lawn is so thick that it prevents the weed seeds from germinating in the dense shade of the blades.  If some weeds appear, rather than use chemical herbicides, the best way to eliminate weeds is still by hand weeding, or for select tough weeds, use NatureZap , a tool that kills the roots with a heating element.

 Alternative, organic, non-chemical methods for killing broad-leaved weeds in specialized lawn grasses, should they arise, are found at Organic – Natural solutions for weeds & pests and TurfMaize – Bioweed N’Feed . Additionally, the web site gives some good tips on how to care for your lawn using organic techniques.

Next time you look at your lawn, remember that the greenest lawns start with the darkest soils! Keep your lawn healthy by keeping your soil healthy.

Literature Cited

Lamp’l, Joe.  2008.  The Green Gardener’s Guide. Simple, Significant Actions to Protect & Preserve Our Planet.  Cool Springs Press. Franklin, Tennessee. 

Lowenfels, Jeff and Wayne Lewis.  2006.  Teaming with Microbes: A Gardener's Guide to the Soil Food Web.  Timber Press, Portland, Oregon.

US News and World Report, May 5, 2005.

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