With the background out of the way in Composting Basics Part 1, we will spend this post laying some ground work for our composting piles (no pun intended) by brushing up on what goes on in a pile as well as what should go IN a pile (and what shouldn’t). As your composting pile begins, the waste and scraps you place in it become home to a variety of microorganisms and insects that use your waste as food. This process generates heat and requires some managing on your part to ensure you get the right balance of items. The following things are true no matter what style of composting you choose, indoors or out.
There are four principal ingredients required by composting organisms to work effectively.
- Carbon — for energy; the microbial oxidization of carbon produces the heat, if included at suggested levels. High carbon materials tend to be brown and dry.
- Nitrogen — to grow and reproduce more organisms to oxidize the carbon. High nitrogen materials tend to be green (or colorful, such as fruits and vegetables) and wet.
- Oxygen — for oxidizing the carbon, the decomposition process.
- Water — in the right amounts to maintain activity without causing anaerobic conditions.
There are general guidelines to what makes good compost, not all food waste is good to make compost out of.
- Yard waste such as grass clippings and fallen leaves are good items to use as bedding or covers for layering.
- Fruit and vegetable trimmings, coffee grounds and grains, along with paper and cardboard torn into strips or hand sized pieces.
- Manure from herbivorous animals like horses, cattle, goats, rabbits and poultry.
Things that should not be added to a compost pile include:
- Meat scraps
- Very fatty, sugary or salty foods
- Chips or sawdust from treated wood
- Clippings from herbicide-treated lawn
- Manure from omnivorous animals (dogs, cats, humans, etc.)
- Slow rotting foods such as citrus peels
- Spicy food or pungent onions
As you work your pile, two things that speed the process are turning the pile, meaning mixing the compost to ensure that everything is evenly distributed and you don’t have wet or dry spots. Balancing the amount of water can be a little tricky; you are looking for moist but not soggy – think of a sponge that has been wrung out. If your pile is too dry after turning, you can add water as needed. If you find it is too moist, adding dry bedding material like cardboard, dried grass or leaves will absorb the excess moisture. If you have an outdoor pile and live in an area that sees frequent or heavy rain, you may consider covering your pile with a tarp as needed to regulate moisture.
With these things in mind, we can begin to plan what style of composting pile we want to tackle and think about what is going on inside the pile as we go along.