Why Should I Compost?

If you had a choice, which would you rather see grow - that precious little garden in your backyard or that ever-expanding landfill down the highway? Probably, you would choose your garden. By composting your yard waste and kitchen scraps, you can reduce the amount of waste that you are "feeding" to the landfill and at the same time produce a "food" for your yard and garden that is as good as any soil conditioner your money can buy.

What is so good about compost? Well, here is a partial list of its benefits:

Compost improves the structure, texture, and aeration of the soil, enabling your plants to develop stronger, deeper root systems.
Compost contains nutrients and trace elemants that are essential to plant growth, and it releases these substances slowly, over time, so that they are available to the plants throughout the growing season.
Compost adds beneficial organisms to the soil.
Compost reduces the need for chemical fertilizers and mulches. This can save you money and can also reduce run-off of these chemicals into streams and rivers.
Using compost can reduce the need for watering your garden.
Composting can reduce by 20% or more the quantity of material you send to the landfill.

In addition, the act of producing and working with compost can help fulfill your need to "get back to nature." You might say that composting is good for the soil and good for the soul.

What, Exactly, Is Composting?

Composting is simply the natural decomposition of organic matter. It is a process that is occurring constantly all around us. Compost is produced through the activity of tiny organisms known as decomposers. Given a favorable environment, they will break down your yard wastes and kitchen scraps into a humus-like material that can serve as an excellent soil amendment for your yard and garden. Once you have established your compost pile, the decomposters go to work almost immediately. At one time or another, your pile will probably be populated by fungi, bacteria, protozoa, roundworms, flatworms, snails and slugs, various types of insect larvae, millipedes, bettles, mites, centipedes and more. Different organisms prefer different organic materials and temperatures; as the conditions in the pile change, the mix of organisms will change, too, with some organisms becoming dormant, dying, or moving to another, more hospitable, part of the pile. Probably the most important thing to know about the organisms involved in composting is that the most desirable decomposers require oxygen. If your pile becomes oxygen deficient, these desirable organisms will die, and anaerobic decomposers (those not requiring oxygen) will take over. The anaerobic decomposers will generate odorous products as well as acids and alcohols that can harm plants. You can make sure that your compost remains oxygen rich simply by turning or mixing the pile every week or so, or anytime you notice it becoming odorous.

How Do I Get Started?

First, choose a location for your compost bin. Here are a few suggestions: Choose a spot that is flat and well drained. A shady location is preferable; direct sunlight may cause the pile to become too hot and to dry out. Place the bin at least 20 feet away from the nearest house. Make sure the bin is close to a source of water (e.g., within reach of a garden hose). Avoid placing the bin against a tree or wooden building; the compost could cause the wood to decay. Once your bin is in place, you can begin immediately to fill it with yard wastes and kitchen scraps (see Table 1 for a list of what can and can not be put into the composter). If you have been stockpiling materials such as leaves or garden wastes, you can put them into the composter all at once, or you can put a small quantity (a 4- to 6- inch layer) of the stockpiled material in the composter and add the rest gradually, alternating it with layers of other materials as they become available. Alternating the types of materials you add to the bin will speed up the decomposition process, especially if you alternate high-carbon materials with high-nitrogen materials and mix the contents of the composter occasionally. See Table 2 for a listing of high-carbon (brown) and high-nitrogen (green) material. It may be helpful, when first building your compost pile, to mix in a small amount (no more than shovelful) of rich garden soil or finished compost; both are good sources of microorganisms essential to decomposition.

Materials that Should & Should Not be in a Compost Pile

Weeds Leaves Bones Mayonnaise
Bread Old Potting Soil Cat Manure Meat
Coffee Grounds Paper Chicken Oils
Egg Shells Sawdust Dairy Products Painted or
Evergreen Needles Straw Diseased Plants Treated Wood
Fruit Tea Leaves Dog Manure Peanut Butter
Fruit Peels & Rinds Vegetables Fish Scraps Salad Dressings
Garden Wastes Wood Ash Lard Vegetable Oil
Grass Clippings Wood Chips Weeds gone to Seed  

Carbon to Nitrogen Ratios for Selected Materials (by Weight)

Material C:N
Materials w/ High Nitrogen "Green" Values
Vegetable Wastes 12:20:1
Coffee Grounds 20:1
Grass Clippings 12-25:1
Cow Manure 20:1
Horse Manure 25:1
Horse Manure w/ Litter 30-60:1
Poultry Manure (Fresh) 10:1
Poultry Manure (w/ Litter) 13-18:1
Pig Manure 5-7:1
Materials w/ High Carbon "Brown" Values
Foliage (Leaves) 30-80:1
Corn Stalks 60:1
Straw 40-100:1
Bark 100-130:1
Paper 150-200:1
Wood Chips & Sawdust 100-500:1

How Do I Maintain the Pile?

You can choose how much effort to put into maintaining your compost pile. If you are not able or inclined to shred and chop your wastes and to water and turn your pile, your organic matter will still turn into compost it will simply take longer. Here are some tips for speeding up the process:

Chop or shred materials before adding them to the composter. Small particles decompose more quickly than large ones. Run over your leaves a couple of times with the lawn mower before adding them to the bin; cut yard trimmings into short pieces; chop up celery stalks.

Keep the pile moist - about like a well wrung sponge.

Mix or turn the pile occasionally, especially during warm weather or if you notice that the pile is hot. Mixing will aerate the pile, providing oxygen needed by the more desirable decomposing organisms, and thereby controlling odors. Once every week or two will probably suffice.

Add nitrogen. Most backyard composters have an over-abundance of carbon, so that the process is limited by the nitrogen available in the pile. Livestock manure (from cows, horses, pigs, chickens, etc.) is rich in nitrogen and can safely be added to your compost pile. Do not add manure from cats, dogs, or other meat eaters.

When Will My Compost Be Ready to Use?

Finished compost will tend to accumulate at the bottom of your bin. It is ready for use when it is dark brown and crumbly, with an earthy aroma. If you have observed the techniques listed above, you may have usable compost in 2 to 3 months; otherwise, your material may require as much as a year or two to completely decompose.

How Do I Use the Finished Compost?

Compost can be used in a variety of ways to benefit your lawn and garden. Here are some suggestions:

In the garden

Spread a 3- or 4-inch layer of compost on top of the garden, and work it into the soil before planting(in spring or late fall); or
Apply the compost as a top dressing to shrubs and garden plants; either leave the compost on the surface or work it into the soil (this can be done several times a year); or
Incorporate compost into feed furrows. Place a handful into each transplant hole before transplanting annuals and perennnials; use several handfuls for shrubs and trees.

On the lawn

When building a new lawn, spread a 2-inch layer of compost over the area and work it into the soil to a depth of 6 inches.
On an existing lawn, use compost as a top dressing by applying it in a uniform layer about 1/4 inch thick. You can use a fertilizer spreader or broadcast the compost by hand, followed by light raking. The best time to top dress is in the fall. (Note: Only compost that has been sifted through a fine screen should be used in this manner. A simple screen can be made using a wooden frame and 3/8- or 1/2-inch hardware cloth.)

In potting mix

You can make your own potting mix by combining fine-textured compost with sand, bark, and vermiculite or perlite.


Where Can I Learn More?

This page was developed to give you all the basic information you need to set up and conduct a backyard composting operation. If you are interested in obtaining more in-depth information, such as details about the decomposition process, things you can do to speed up the process, or ways to alter the characteristics of your compost, there are a number of resources that you can take advantage of.

There are many good books and pamphlets about backyard composting. Check your local libraries and bookstores - they are sure to have information on the subject. Look in sections related to such topics as gardening, nature, or the environment. And dont forget the periodicals section, with its supply of magazines devoted to gardening and lawn care. The internet is also a great way to get lots of helpful information about composting.

In addition to the Department of Natural Resources and Environmental Control (which produced this page), these agencies and organizations have information about composting:

The Delaware Solid Waste Authority
(call the Citizens Response Line at 1-800-404-7080).

Mid-Atlantic Composting Association.
(Call Pat Condon, President, (410) 221-6057).

The University of Delawares Cooperative Extension Office in each county
(New Castle County: 831-2506; Kent County: 697-4000; Sussex County: 856-7303)
The New Castle County Extension Office, through its Master Composters Program, gives workshops, classes, and demonstrations on composting throughout the year.

Good luck, and thank you for composting!

Department of Natural Resources and Environmental Control
Division of Air and Waste Management and Non-Point Source Program
89 Kings Highway
Dover, Delaware 19901
(302) 739-9403

The Department of Natural Resources and Environmental Control is an equal opportunity employer. No person or group shall be excluded from participation, denied benefits, or subjected to discrimination on the basis of race, national origin, or handicap.

Funding for this project was provided by a Nonpoint Source Grant made available through the U.S. Environmental Protection Agency, Region III.


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