Hello fellow Earthlings and welcome to another edition of Organically Speaking. In this issue of Awareness Magazine, we will be discussing the nuts and bolts of backyard compost-making as well as a brief mentioning of some of the wonderful things that composting does for the garden and the wallet. So let's get to work...
There are three critical elements to making good/nutritious backyard compost, they are: 1. A balance of raw organic materials 2. Air (smog alerts not required) 3. Water
The art of making good compost involves the integration of these three components to allow decomposition of the organic materials in the most efficient manner. Composting is just a modification of the natural process of decay that occurs in nature, which maintains and enhances the nutrients in the cycle of life. The most common type of backyard composting is hot or therm-ophyllic composting. This is where organic matter is broken down much more rapidly in the presence of heat energy.
The first step is to find the raw or organic materials that will make up your compost
heap. There are two basic types of matter that go into the building of your compost pile:
1. MATERIALS HIGH IN CARBON These are woody/dry materials like sawdust, straw, fallen leaves and dry grass clippings and shrub and tree prunings. A good thing to remember is that the older and dryer/mature the material is, the higher the carbon content.
2. MATERIALS HIGH IN NITROGEN Green/wet materials like fresh grass clippings, kitchen wastes, fresh green weeds or trimmings from the vegetable/flower gardens and manures. Another good thing to remember is that the greener the material, the higher the nitrogen content.
Material high in carbon is usually the ingredient most readily available for composting, but it is also the limiting factor in the speed upon which compost is formed. Carbon rich material breaks down and decomposes slowly. To be sure that your compost heap is working fast, it is crucial to properly balance carbon and nitrogen-rich materials in the compost mix.
The location of the composting operation on your property is also a fairly important issue for the residential gardener on a normal-sized lot. It is, of course, not very smart to locate a compost pile in the front of your home. Your neighbors will respect the fact that you recycle organic matter, however it will be debatable how they feel about the aesthetics of a heap of green waste visible from the street. Position your compost heap in an area of the backyard that is protected from the drying winds of winter and the hot sun of summer. A good rule of thumb is that łthe more exposed the compost pile is, the more water it will take to ensure a proper moisture content.
When building your compost heap, you simplify the process of balancing carbon and
nitrogen content by layering the ingredients. It is best to put layers of carbon rich
(browns) in 6-8 inch layers next to layers high in nitrogen (greens) that are
approximately 3-4 inches thick. By stacking these layers on top of one another you form
the heap/pile. It is better to use this method than to have a few thicker layers of
material. The thin layers will allow for more efficient decomposition of the organic
matter/raw materials. Those raw materials consist of the following :
1. Loosen the soil in the compost heap area and make a base of really coarse materials. Sunflower or cornstalks do nicely. If these are not available use twigs from your prunings. This will allow for air to flow at the bottom of the pile and will accelerate the decomposition process. Add Water! Get it nice and wet.
2. On top of this base layer add a layer of carbon rich (browns ) 6-8 inches thick. Water it again!
3. On top of the browns you add a layer of nitrogen rich (greens) material about 3-4 inches thick. Water some more!
4. At this stage some people like to add about a half inch of regular garden soil on top of the greens to bring micro organisms into the heap a little faster and to help in reducing the leaching of minerals and may aid in the preventing of nitrogen gas escaping.
5. Continue this layering until the pile has reached a minimum height of 3 feet. Wet each layer thoroughly to ensure proper moisture content. Kitchen waste may not require watering if it is already pretty wet.
6. On top of the finished pile add a thin layer of regular garden soil about 2-3 inches thick to retain moisture and nutrients within the heap. Then cover the entire pile with a thick layer of straw hay or alfalfa hay; this will serve as an insulator from heat and cold. Water again really well. The construction is complete!
In a well-constructed compost heap, process of decomposition generates a lot of heat. Temperatures upwards of 150 degrees are not uncommon. This high heat is crucial for the killing of any weed seeds and pathogens that may exist in the matrix. Monitor the temperatures with a compost thermometer and turn the pile over when temperatures begin to fall. This may only take two to three weeks to occur. After turning the compost, let it cook for about another two to three weeks or until it cools down again. Then the compost is ready to use as a mulch or a wonderful, rich soil amendment.
In future columns we will discuss the benefits of composting, but for now any time you read the word mulch or compost, you'll know what I mean and how it is made. Next time we will be discussing the preparation of the garden for a hopefully wet winter. See you in the Garden!
Got Questions! Call the toll-free gardener's help line for free advice at 1.888.514.4004 or e-mail firstname.lastname@example.org Don Trotter operates The Organic Gardener's Resource and Design Centre in Encinitas, CA. He is also a consulting horticulturist and an award-winning garden designer.
Return to the November/December Index page