Home and Living

Creating a compost pile is one of the best investments you can make in your garden. Composting is the keystone to a successful, sustainable organic garden. Rather than sending your garden wastes to the landfill and spending upwards of $50 a year on fertilizers, your compost pile allows you to invest your precious plant materials to produce nature’s finest fertilizer. Compost will add organic matter naturally, prevent plant and soil diseases, correct sandy or clay soil structure, make a great mulch or top dressing, provide a variety of nutrients when plants need them, aerate soil, improve drainage, prevent erosion, neutralize toxins, and recycle garden wastes.

So, how do you compose your compost pile? If you put organic material in a pile, it will eventually break down to composted matter. However, there are many ways to control this magical process through the size and shape of the pile and the various materials added to it. You can have a “cold pile” that you add materials, such as kitchen scraps, on an ongoing basis. This pile will compost rather slowly (1-2 years). The faster route requires the creation of a “hot pile”, which should reach temperatures of 140° F. This pile is created with all the materials it will need, so by adding water and turning it regularly, you can help this pile finish composting within 6-8 months. All healthy compost piles require the following items; Browns - “Browns” are dry materials such as leaves or straw that provide carbon. Browns should compose roughly one-quarter of your pile. Greens - “Greens” are green materials such as grass or weeds from your garden that provide nitrogen. Greens should compose roughly one-half of your pile. Soil - Adding soil brings organisms that decompose (this is particularly important for piles that are on concrete or in containers off the ground) and provides a structure for the finished product. Soil should compose roughly one-quarter of your pile (less for heavy clay soil). Water - The organisms in your pile need a moist environment to live in, especially in a desert climate. The inside of your pile should have the consistency of a wrung-out sponge. Air - Turning your pile adds air to the mix. Organisms in the pile need a source of oxygen if they are going to thrive.

There are a few different ways to compose your composting process. A gardener’s choice of composting method should be convenient and reflect personal preference and aesthetics. Large farming operations often choose to create windrows, which are long, worm-shaped piles which are ideal for machinery. Home gardeners may opt for composting underground through sheet-composting, where plant material is buried under soil for a few months. A typical compost pile should be about 3 feet high and 3 feet wide. This pile can be contained in a bin made of wood or plastic. Some people even use wire cages. Before creating a pile, loosen the soil where you intend to build it. Then layer a few sticks or more woody material for the base level of the pile. This improves drainage and creates an open invitation for decomposers to start working!

Many different kinds of organisms work together to make compost happen. The types of decomposers you find within your pile will vary according to its stage of decomposition. These stages may be measured by temperature. Below 55° F, most microbes will be dormant. The microbes existing between 55-70° F are called psychrophiles, which burn carbon and raise the temperature of the pile, making way for mesophiles, which thrive at temperatures of 70-90° F. Mesophiles are the “work horses” of the pile, consuming everything in sight which raises the temperature of the pile to over 100° F. Between 90-200° F thermophiles take over, producing humid acid which improves soil structure, raises temperatures, and brings the pile to a finished state.

The finished product, called humus, is a dark, rich soil that is cake-like when you pick it up in your hands. Some studies suggest that uncured or partially cured compost (3-9 weeks old) is not nearly as helpful for soil as fully cured compost. The more often you turn your pile, the faster it will produce finished compost. A compost pile should not smell bad. If your pile smells, it is probably too wet or the carbon: nitrogen ratio is off. The carbon: nitrogen ratio should be anywhere from 25:1 to 40:1 Before starting a pile, dig up the soil where your pile will be (to welcome organisms to the pile), and lay down thick materials such as sunflower stalks or sticks to encourage good aeration. Don’t add weeds such as bindweed or others that have gone to seed unless your pile is hot enough to sterilize the seeds (140° F). While most manure is a great source of nitrogen for your pile, don’t add wastes from carnivorous animals (cats, dogs, humans), because they may contain harmful bacteria.

If you compost at home, do not use meat, dairy, or oily foods. Food wastes can attract rodents and should be deposited in closed composting containers. If you do not have space to create a compost pile outside, don’t worry! You can compost indoors using red wiggler worms (eisenia foetida). All you need is a lidded container with holes drilled in the top and sides for proper aeration. It is also recommended that you drill holes in the bottom for drainage. The worms will require bedding (such as newspaper), and food from your kitchen. Remember to avoid meat, dairy, bread products, oily and citrus foods. The resulting compost is great for houseplants!