Few things are better for your plants and for the environment than home-made garden compost, yet why is making it never quite as straightforward as the experts would have us believe?
Perhaps unrealistic expectations, coupled with the modern desire for instant results, are mainly to blame. The commercial garden industry, anxious to sell us a fancy machine or secret ingredient that promises to make compost in days, merely adds to our feeling of inadequacy. But don’t panic, this book is here to help take the mystery and fuss out of making compost.
It makes clear that compost making doesn’t need to be hard work, need cost almost nothing, and that the only secret ingredient you need is patience. It doesn’t prescribe any particular approach, but it does explain that although things will go wrong, if you understand the basic principles and learn from your mistakes, you will soon arrive at a method that works for you and suits your kind of gardening.
What is compost?
To gardeners, compost is considered “black gold” because of its many benefits in the garden. Compost is a great material for garden soil. Adding compost to clay soils makes them easier to work and plant. In sandy soils, the addition of compost improves the water holding capacity of the soil. By adding organic matter to the soil, compost can help improve plant growth and health.
Composting is also a good way to recycle leaves and other yard waste. Instead of paying a company to haul away leaves, you can compost the leaves and return the nutrients to your garden. Instead of buying peat moss, save money and make your own compost!
The composting process
The composting process involves four main components: organic matter, moisture, oxygen, and bacteria.
Organic matter includes plant materials and some animal manures. Organic materials used for compost should include a mixture of brown organic material (dead leaves, twigs, manure) and green organic material (lawn clippings, fruit rinds, etc.). Brown materials supply carbon, while green materials supply nitrogen. The best ratio is 1 part green to 1 part brown material. Shredding, chopping or mowing these materials into smaller pieces will help speed the composting process by increasing the surface area.
For piles that have mostly brown material (dead leaves), try adding a handful of commercial 10-10-10 fertilizer to supply nitrogen and speed the compost process.
Moisture is important to support the composting process. Compost should be comparable to the wetness of a wrung-out sponge.
If the pile is too dry, materials will decompose very slowly. Add water during dry periods or when adding large amounts of brown organic material.
If the pile is too wet, turn the pile and mix the materials. Another option is to add dry, brown organic materials.
Oxygen is needed to support the breakdown of plant material by bacteria. To supply oxygen, you will need to turn the compost pile so that materials at the edges are brought to the center of the pile. Turning the pile is important for complete composting and for controlling odor.
Wait at least two weeks before turning the pile, to allow the center of the pile to “heat up” and decompose. Once the pile has cooled in the center, decomposition of the materials has taken place. Frequent turning will help speed the composting process.
Bacteria and other microorganisms are the real workers in the compost process. By supplying organic materials, water, and oxygen, the already present bacteria will break down the plant material into useful compost for the garden. As the bacteria decompose the materials, they release heat, which is concentrated in the center of the pile.
You may also add layers of soil or finished compost to supply more bacteria and speed the composting process. Commercial starters are available but should not be necessary for compost piles that have a proper carbon to nitrogen ratio (1 part green organic material to 1 part brown organic material).
In addition to bacteria, larger organisms including insects and earthworms are active composters. These organisms break down large materials in the compost pile.
How long does it take?
The amount of time needed to produce compost depends on several factors, including the size of the compost pile, the types of materials, the surface area of the materials, and the number of times the pile is turned.
For most efficient composting, use a pile that is between 3 feet cubed and 5 feet cubed (27-125 cu. ft.). This allows the center of the pile to heat up sufficiently to break down materials.
Smaller piles can be made but will take longer to produce finished compost. Larger piles can be made by increasing the length of the pile but limiting the height and the depth to 5 feet tall by 5 feet deep; however, large piles are limited by a person’s ability to turn the materials. You may also want to have two piles, one for finished compost ready to use in the garden, and the other for unfinished compost.
If the pile has more brown organic materials, it may take longer to compost. You can speed up the process by adding more green materials or a fertilizer with nitrogen (use one cup per 25 square feet).
The surface area of the materials effects the time needed for composting. By breaking materials down into smaller parts (chipping, shredding, mulching leaves), the surface area of the materials will increase. This helps the bacteria to more quickly break down materials into compost.
Finally, the number of times the pile is turned influences composting speed. By turning more frequently (about every 2-4 weeks), you will produce compost more quickly. Waiting at least two weeks allows the center of the pile to heat up and promotes maximum bacterial activity. The average composter turns the pile every 4-5 weeks.
When turning the compost pile, make sure that materials in the center are brought to the outsides, and that materials from the outside edges are brought to the center.
With frequent turning, compost can be ready in about 3 months, depending on the time of year. In winter, the activity of the bacteria slows, and it is recommended that you stop turning the pile after November to keep heat from escaping the pileís center. In summer, warm temperatures encourage bacterial activity and the composting process is quicker
Using compost in the yard
Incorporate compost into your garden as you prepare the soil in the spring. Cover the area with 3-4 inches of soil and till it in to at least the upper 6 inches of soil. Add compost to soil in vegetable gardens, annual flower beds, and around new perennials as they are planted.
You may also use compost as mulch around flower beds, vegetable gardens, or around trees or shrubs in landscape beds. Apply a 3 inch layer. Be careful not to apply mulch close to the main stem or trunk of the plant.
What To Compost
You may use:
- Some manures (cow, horse, sheep, poultry, rabbit, llama)
- Lawn clippings
- Vegetable or fruit wastes, coffee grounds
- Shredded newspaper or white, unglazed office paper
- Trimmed plant materials
- Shredded stems and twigs
- Meat or dairy scraps
- Some manures (cat, dog, swine, and carnivore manures)
- Glazed, colored printed magazine paper
- Diseased plants or plants with herbicides applied
Types of Compost Bins
Holding units are low maintenance, and are good choice for those with limited space, such as apartment dwellers. These units do not require turning, however the lack of aeration causes the composting process to take 6 months to 2 years. Holding units are available from stores and catalogs.
Portable bins are similar to holding units, except that they can be taken apart and moved. Materials can also be mixed with this type of bin. Plastic units are available for purchase, or you may construct a bin from wire fencing framed in wood.
Turning units are designed so that they may be aerated. Turning units produce compost faster because they supply oxygen to the bacteria in the pile. These units may also have less odor problems, which are associated with poor aeration.
Turning units may be either a series of bins or a structure that rotates, such as a ball or barrel. These systems often cost more and are more difficult to build. Materials must also be saved until a unit can be filled to the correct level. Once these units are filled and the turning process begins, new materials should not be added.
Heaps are an option for those who do not wish to build or purchase a bin structure. Turning the heap is optional, but remember the composting process will be slowed if the pile is not turned. Woody materials may take a very long time to decompose with this method, and food scraps may attract pests.
Sheet composting can be done in the fall. With this method, a thin layer of materials such as leaves (that have not been composted) are worked into the garden. By spring, the material will be broken down. The decomposition process ties up soil nitrogen, making it unavailable to other plants. Because of this, sheet composting should only be done in the fall when the garden is fallow.
Soil incorporation is also known as trench composting. Organic material are buried in holes 8-15 inchesdeep, and then covered with soil dug from the hole. Decomposition takes about a year, as limited oxygen slows the process. It is recommended to avoid planting that area for a year, as the nitrogen available to plants may be limited by the decomposition process.
Where to place the compost
Placing the compost bin in your yard depends on both functional and aesthetic needs.
For the compost bin to function properly, place the compost pile in an area with good air circulation. Do not place the pile so that it is in direct contact with wooden structures, as this will cause decay. It is best to locate the pile in partial shade, but this is not a necessity.
You may want to locate it close to the garden and close to a water source. If kitchen scraps will be added regularly, it may be more convenient to have the pile near the kitchen.
You may also want to screen the pile from view with a fence or by placing it behind shrubs or a taller structure. You may also wish to avoid placing the pile near outdoor entertaining areas.
Video’s on composting
In short, plants need three key things from soil; water, air, and nutrients, and compost helps provide all three.