Compost is often called “garden gold,” and for good reason. Adding compost to garden soil improves more than just plant growth. Compost increases organic matter in the soil, improves water-holding capacity in sandy soils, helps drainage in heavy clay soils, and provides valuable nutrients for plants. Best of all, composting is a great way to recycle kitchen and yard waste instead of sending it to the landfill.
Backyard composting may seem complicated at first, but it really comes down to creating the right environment for beneficial microorganisms to do the work for you.
Many common household and yard materials can be added to a compost pile. Good materials include leaves, grass clippings, straw, and other non-woody plant debris. Kitchen scraps such as vegetable peels, fruit waste, coffee grounds, and eggshells also work well. Paper products like shredded newspaper or office paper can also be composted.
Larger branches, logs, and twigs should be chipped or shredded before adding them to the pile. Smaller pieces break down much faster than large chunks of wood.
There are also a few things that should stay out of the compost pile. Diseased plant material can spread problems back into the garden. Weeds that contain seeds or spread aggressively may survive the composting process and create future headaches. Meat, fish, bones, dairy products, oils, grease, and fatty foods should also be avoided because they attract pests and create unpleasant odors. Pet and human waste should never be added due to the risk of disease organisms.
One of the keys to successful composting is balancing carbon and nitrogen materials. This balance affects how quickly microorganisms can break down organic matter.
Materials high in nitrogen are often called “greens.” These include grass clippings, vegetable scraps, fruit waste, and aged livestock manures such as horse, cow, or poultry manure. Nitrogen-rich materials help heat the compost pile and fuel microbial activity.
Materials high in carbon are known as “browns.” These include dry leaves, straw, newspaper, pine needles, sawdust, and wood chips. Carbon materials provide energy for the microorganisms and help create airflow within the pile.
A compost pile with too much carbon may remain cool and decompose very slowly. A pile with too much nitrogen can heat up rapidly, become slimy, and develop an ammonia smell. Layering green and brown materials, similar to building layers in lasagna, is a simple way to maintain a good balance.
The goal is to create ideal conditions for aerobic bacteria, the beneficial microorganisms that thrive with oxygen and produce little odor.
Pile size matters too. Compost piles should be large enough to hold heat but small enough to allow air movement. A pile about 3 feet wide, 3 feet long, and 3 feet tall is usually ideal. Moisture is also important. The pile should feel similar to a wrung-out sponge—moist, but not soaking wet.