Vegetable Gardening - Handbook for Beginners
Chapter 2.4.

Composting is a method of producing a nutrient rich soil amendment (plant food) by using naturally occurring beneficial fungi and bacteria to break down organic waste. The simple process of composting allows large amounts of household, yard, and/or animal waste (do not use manure from cats, dogs, etc.) to be transformed into smaller piles of natural soil conditioner. The composting process involves controlled biological decomposition of organic material, sanitization through the generation of heat, and stabilization of the final product to make it beneficial to plant growth. As bacteria, yeast and fungi digest the waste, they make nutrients more available. When compost is added to soil, the nutrients are slowly released over time, allowing easy uptake by plants.

There are many ways to make compost: underground, above ground, in bins, in boxes, in pits, in bags, in barrels, in strips, in sheets, and in trenches. The composting process can take as few as fourteen days or as many as fourteen months, depending on the method. Each method has its own advantages, but they all have the same basic requirements: air, moisture, nitrogen, bacteria, heat, sufficient size, and plenty of organic matter. These elements are critical for the compost pile to heat up correctly.

Image

Hot composting yields compost quickly, in as little as two weeks, and destroys most pathogens and weed seeds. This process relies on frequent turning of the pile, as often as once a day, to ensure even heating. The carbon-to-nitrogen ratio must be controlled with this technique: this means the composition of the pile needs to be approximately 1 part of brown (high in carbon) material, such as dry grass, dry yard trimmings, leaves and shredded paper, to every one part of green (high in nitrogen) material, including food waste, coffee and tea grounds, fresh cut grass and hair.

Cold composting is a much less labor-intensive but more lengthy process, taking three months or longer. Turning is required just once every three to-six weeks, if at all. Materials can be continually added in layers alternating green and brown to the existing pile. Since high temperatures are not achieved, pathogens and weed seeds aren’t reliably destroyed.

Half green (e.g. vegetable scraps, grass clippings), half brown (e.g., leaves, shredded paper). A pile with too much green will smell; a pile with too much brown will take longer to break down. Add a bit of soil to introduce microorganisms that initiate the composting.

Do NOT compost poisonous, diseased, or insect infected plants; weeds, dog or cat manure, meat, fish, dairy products, or anything with fat or oil.

Chop/shred the ingredients into small pieces. The smaller they are, the faster they will break down.

Composting Methods

Conditions for standard composting: 

• Size: large enough to hold heat, but small enough to allow air to reach the center of the pile - 3’ x 3’ to 5’ x 5’.
• Air: turn the pile every 3-7 days for hot composting and every 3-6 weeks for cold composting.
• Water: the pile should be as moist as a wrung-out sponge.

When is the compost done?

• The pile will shrink, losing about 1/3 of its volume.
• The temperature will drop.
• It will be dark brown and crumbly with an earthy smell.
• You should no longer be able to tell what each of the individual ingredients was.
• Allow compost to age for two weeks before you add it to the soil around plants. Or, incorporate but don’t sow seeds or transplant seedlings for two weeks.

Composting Systems

The table below describes several different types of composting systems.

Compost Troubleshooting Guide

Previous ← Chapters → Next   or   Return to the Table of Contents of this Handbook.