Joe E. Heimlich
The Don't Bag It lawn care plan can save the homeowner time, energy and money, and reduce the amount of waste going to our landfills. The principle is simple: return clippings to your lawn. By leaving your clippings on the lawn and allowing them to work their way back into soil, you can realize these benefits and still maintain a beautiful, green lawn.
In fact, grass clippings contain valuable nutrients that can generate up to 25 percent of your lawn's total fertilizer needs. A hundred pounds of grass clippings can generate and recycle as much as three to four pounds of nitrogen, one-half to one pound of phosphorus, and two to three pounds of potassium back to the lawn. These are the three most important nutrients needed by lawns and commonly supplied in lawn fertilizers. The other good news is that grass clippings do not contribute to thatch (an organic debris layer between the soil and live grass) since grass clippings are 75-85 percent water and decompose readily.
Why, then, do many homeowners bag grass clippings? Basically, it is a personal preference and habit most homeowners have acquired. Another reason is that bagging does ensure that no clippings remain on the lawn to detract from lawn quality and aesthetics. Proper lawn care practices will usually eliminate surface clipping debris and ensure a successful Don't Bag It program.
Mow your lawn often and let the clippings lie. This is the best use for grass clippings. Composting is another solution. Composting is a practical and convenient way to handle your yard wastes. It can be easier and cheaper than bagging these wastes and, in some cases, paying to have them removed. Compost also improves your soil and the plants growing in it. If you have a garden, a lawn, trees, shrubs or even planter boxes, you have a use for compost.
Compost returns organic matter to the soil in a usable form. Organic matter in the soil improves plant growth by: loosening heavy clay soils to allow better root penetration; improving the capacity to hold water and nutrients in sandy soils; and adding essential nutrients to any soil. Improving your soil is the first step toward improving the health of your plants. Healthy plants help clean our air, conserve our soil and beautify our landscapes.
Yard wastes and kitchen scraps use up valuable space in our landfills - space that is running out fast! These materials make up 20-30 percent of all household wastes. Because of their high moisture content, yard wastes also lower the efficiency of incineration systems. By composting these wastes at home, you can help protect the environment, save money and improve your own soil at the same time.
Yard wastes such as fallen leaves, grass clippings, weeds and the remains of garden plants make excellent compost. Other good additions to a compost pile include sawdust, wood ash, and kitchen scraps such as fruit and vegetable peelings, egg shells and coffee grounds. Care must be taken when composting kitchen scraps. Do not compost meat, bones and fatty foods such as cheese, salad dressing and cooking oil. These foods will attract pests and slow decomposition.
With these principles in mind, everyone can make excellent use of their organic wastes.
What happens in a compost pile? Bacteria, the most numerous and effective microbes, are the first to break down plant tissue. Fungi and protozoans soon join the bacteria.
Anything growing in your yard is potential food for these microbes. Microorganisms use the carbon in leaves or woodier wastes as an energy source. Nitrogen provides the microbes with the raw element of proteins to build their bodies.
Everything organic has a ratio of carbon to nitrogen (C:N) in its
tissues. A C:N ratio of 30:1 is ideal for the activity of compost
microbes. This balance can be achieved by mixing. The following table
can help you judge the ratio of your compost ingredients.
| Carbon:Nitrogen Ratio | |
|---|---|
| Food Wastes | 15:1 |
| Wood | 700:1 |
| Sawdust | 500:1 |
| Straw | 80:1 |
| Grass Clippings | 19:1 |
| Leaves | 60:1 |
| Fruit Wastes | 35:1 |
| Rotted Manures | 20:1 |
| Cornstalks | 60:1 |
| Alfalfa Hay | 12:1 |
The more surface area the microorganisms have to work on, the faster the materials decompose. Chopping your garden wastes with a shovel or machete, or running them through a shredding machine or lawn mower will speed their composting.
A large compost pile will insulate itself and hold the heat of microbial activity. Its center will be warmer than its edges. Piles smaller than three feet cubed (27 cu. ft.) will have trouble holding this heat, while piles larger than five feet cubed (125 cu. ft.) don't allow enough air to reach the microbes at the center. These proportions are of importance only if your goal is a fast, hot compost. Slower composting requires no exact proportions.
All life on Earth, including compost microbes, needs a certain amount of water and air to sustain itself. Microbes function best when the compost heap has many air passages and is about as moist as a wrung-out sponge. Extremes of sun or rain can adversely affect this moisture balance.
The faster the composting, the hotter the pile. If you use materials with a proper C:N ratio, provide a large amount of surface area, a big enough volume, and adequate moisture and aeration, you'll have a hot, fast compost and will probably want to use a turning bin. If you just want to deal with your yard wastes in an inexpensive, easy, non-polluting way, a holding bin will serve you well.
Remove grass and sod cover from the area where you will construct your compost pile to allow materials direct contact with soil microorganisms. The following "recipe" for constructing your compost heap is recommended for best results:
A properly made heap will reach temperatures of about 140 degrees F in four to five days. At this time, you'll notice the pile "settling," a good sign that your heap is working properly.
After 5-6 weeks, fork the materials into a new pile, turning the outside of the old heap into the center of the new pile. Add water if necessary. You shouldn't need to turn your heap a second time. The compost should be ready to use within three to four months. A heap started in late spring can be ready for use in the autumn. Start another heap in autumn for use in the spring.
You can make compost even faster by turning the pile more often. Check the internal temperature regularly; when it decreases substantially (usually after about a week), turn the pile.
Compost is ready to use when it is dark brown, crumbly and earthy-smelling. Let it stabilize for a few extra days and screen it through a 1/2" screen if you want the finest product. Turn your soil, apply a 1"-3" layer of compost, and work it in well, up to one pound (a heaping, double handful) per square foot. Table 1 is a guide to more efficient composting.
| Table 1. Guide to More Efficient Composting | ||
|---|---|---|
| Symptoms | Problem | Solution |
| The compost has a bad odor. | Not enough air. | Turn it. Add dry material if the pile is too wet. |
| The center of the pile is dry. | Not enough water. | Moisten and turn the pile. |
| The compost is damp and warm only in the middle. | Too small. | Collect more material and mix the old ingredients into a new pile. |
| The heap is damp and sweet-smelling, but still will not heat up. | Lack of nitrogen. | Mix in a nitrogen source like fresh clippings fresh manure, or bloodmeal. |
Bins made with prefabricated snow fencing are simple to make and easy to move and store. To build this bin, buy the appropriate length of prefabricated fencing, and fasten two-by-fours as corner posts to the bottom to form a square.
One easy to make, economical container requires only a length of woven wire fencing. Multiply the diameter you want for the compost heap by 3.2 for the length of fencing to purchase. Fasten the ends with wire or three or four small chain snaps (available at any hardware store) to make a circle.
Compost bins can be made with bricks, cement blocks or rocks. Just lay the blocks without mortar; leave spaces between each block to permit aeration. Pile them up to form three sides of a square container or a three-bin unit. This bin is sturdy, durable and easily accessible.
Covered wooden bins allow convenient protection from pests and heavy rains. Construct bins with removable fronts or sides so that materials can be easily turned. Old wooden pallets can be used for construction. Wire mesh can be substituted for wooden sides to increase air flow.
Prefabricated compost bins can also be purchased through most gardening catalogues.
The portable holding bins are the simplest way to compost. Which wastes? Non-woody yard wastes are the most appropriate. Avoid composting diseased or infested plants.
How? Place the holding bin where it is most convenient. As weeds, grass clippings, leaves and garden debris are collected, they are dropped into the bin. This method will take from six months to two years to produce compost. Chopping or shredding wastes, alternating high-carbon and high-nitrogen materials, and keeping up good moisture and aeration will all speed the process.
This is a series of three or more bins that allows you to make compost in a short time by turning the materials on a regular schedule. Turning bins are most appropriate for gardeners with a large volume of yard waste and the desire to make a high-quality compost. You can also turn your compost with only one bin by removing the bin from around the heap when it's time to turn it, set up the empty bin nearby, and fork the material into it. Which wastes? A wide variety of organic materials will produce a more nutrient diverse compost. If your own kitchen, yard and garden do not generate enough material to fill your bin, ask your neighbors for their clippings and leaves, or start a neighborhood composting project.
Woody yard wastes, leaves and grass clippings can be used as a mulch for weed control and water retention by simply spreading them beneath plants. For woody materials up to 1" in diameter, rent or purchase a chipper/shredder, or cut with hand tools. Tree services, if they are in your neighborhood, often will deliver wood chips free. Chips can also be used for informal garden paths.
All yard wastes will work as a mulch and for composting, but do not use diseased or infested plants. The long-term environmental impact of herbicides and pesticides is not fully understood. Grass clippings treated with these should not be used as a mulch immediately after mowing, but should be composted. While a common practice, use of compost containing grass clippings treated with herbicides and pesticides is not recommended for vegetable gardens.
All educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, creed, religion, sexual orientation, national origin, gender, age, disability or Vietnam-era veteran status.
Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension.
TDD No. 800-589-8292 (Ohio only) or 614-292-1868