The Basics of Composting

Published by Kara Harders, Small Acreage Management Specialist 

Composting is a natural process we can utilize to help break down and recycle materials which would have otherwise been considered trash or waste. Materials including food scraps, garden byproducts, and other organic “trash” can become the magical soil amendment we know as compost!

Because composting is a natural process, it can be induced by following some basic rules and creating ideal conditions for the process to happen. While people may think they are the ones composting it is really bacteria, fungi, molds, and worms doing all the heavy lifting. When we compost it is important to keep these organisms happy and healthy so they can do what they do best, turn trash into soil gold! Luckily, they only need a few things to do what they do best.

Food! (Nitrogen and carbon rich)

These composting critters work best when given about a 30:1 Carbon to Nitrogen ratio. The carbon source could be dead plants, bedding, grass clipping, leaves or even shredded office paper. The nitrogen source could be fresh grass cuttings, food scraps or animal manure.

Moisture

Like all living things, water is essential to the life in your compost heap. Most of the organisms breaking down materials in your compost pile live in the film of moisture around the “ingredients” in the pile. Too little moisture and they will die or become dormant and too much moisture and they will drown (and the pile will smell BAD). Aim for a pile that feels damp, like a wrung-out sponge. If the pile gets too dry spray it lightly with a garden hose and try to keep it covered with a tarp in a shady area to retain moisture and to keep out heavy rains. 

Form

Compost needs to be grouped to maintain moisture and heat; therefore, the structure of your compost needs to be in a heap of sorts. This may seem obvious, but there are a few critical details.

Consider where you are putting your pile, avoid spots in direct sunlight for much of the day as this can dry out your pile. You should also avoid areas where water collects or drains. Compost piles are rich in nutrients that can be harmful to water ways and contribute to nutrient pollution. Think about keeping water from running through the pile when it rains or snow melts.

An ideal size is about on cubic yard, a pile this size can be built over time (cool composting) or all at once (hot composting), a benefit to doing hot composting is the sterilization of some weed seeds. Large heaps made all at once with the correct balance of materials and moisture can break down materials so fast the internal temperatures of these piles can reach 160ºF! Smaller piles wont hold heat as well and can dry out quickly if done outside of a container, but they will be easier to turn. Speaking of turning…

Aeration

All those composting organisms you are after also need to breath, in addition to design, to get them oxygen you will need to “turn” the pile.

Ideally, your compost pile will sit on some coarse materials to help allow air travel in from the base. When setting up the pile make an effort to use materials which create air pockets, such as stems, stalks, wood chips and other rigid materials. These will help to draw air up and out of the pile.

Use a composting thermometer to gauge the inside temperature. When it reaches 140ºF, give it a turn and water as needed. Turning the compost will also help get air to the organisms doing the dirty work. You can turn the compost as often as the temperature reaches 140ºF. It is recommended to let the pile go through three heating cycles to help sterilize weed seeds.

Particle size

While it is not always possible or realistic to select items for your compost pile by size it can make it more efficient. Because the organisms breaking down material work on the outer surface of the composted materials, they work much quicker when the surface area is large in relation to the particle size’s mass, in other words, small pieces break down much faster. You can mulch logs/branches, cut stalks to less than 5”, mow leaves with the lawn mower, and break up manure clumps.