How to Make Compost from Waste

Composting is good way to recycle leaves and other yard waste. Instead of paying a company to haul away leaves, you can compost the leaves and return the nutrients to your garden. Instead of buying peat moss, save money and make your own compost!

You can produce compost very quickly by cutting your yard waste into small pieces and turning it often. If it’s cut to between 1 1/2 and 1/2 inch in size, yard waste will decompose rapidly. You may need a shredder for woody waste, but a lawnmower is an excellent tool for cutting up the rest.

What To Compost

• Fruits and vegetables
• Eggshells
• Coffee grounds and filters
• Tea bags
• Nut shells
• Shredded newspaper
• Cardboard
• Paper
• Yard trimmings
• Grass clippings
• Houseplants
• Hay and straw
• Leaves
• Sawdust
• Wood chips
• Cotton and Wool Rags
• Hair and fur
• Fireplace ashes

What Not To Compost and Why

• Black walnut tree leaves or twigs
  – Releases substances that might be harmful to plants
• Coal or charcoal ash
  – Might contain substances harmful to plants
• Dairy products (e.g., butter, milk, sour cream, yogurt) and eggs*
  – Create odor problems and attract pests such as rodents and flies
• Diseased or insect-ridden plants
  – Diseases or insects might survive and be transferred back to other plants
• Fats, grease, lard, or oils*
  – Create odor problems and attract pests such as rodents and flies
• Meat or fish bones and scraps*
  – Create odor problems and attract pests such as rodents and flies
• Pet wastes (e.g., dog or cat feces, soiled cat litter)*
  – Might contain parasites, bacteria, germs, pathogens, and viruses harmful to humans
• Yard trimmings treated with chemical pesticides
  – Might kill beneficial composting organisms * Check with your local composting or recycling coordinator to see if these organics are accepted by your community curbside or drop-off composting program.

The composting process

Composting relies on microorganisms to break down organic waste. That means you need to provide optimal nutrients, water, temperature and oxygen levels for the best results.

The right temperature can really speed up the process.

Organic matter includes plant materials and some animal manures. Organic materials used for compost should include a mixture of brown organic material (dead leaves, twigs, manure) and green organic material (lawn clippings, fruit rinds, etc.). Brown materials supply carbon, while green materials supply nitrogen. The best ratio is 1 part green to 1 part brown material. Shredding, chopping or mowing these materials into smaller pieces will help speed the composting process by increasing the surface area.

For piles that have mostly brown material (dead leaves), try adding a handful of commercial 10-10-10 fertilizer to supply nitrogen and speed the compost process.

Temperature

A temperature range of 70 to 140 degrees is necessary for the microbes to operate, but they will work faster at the higher end of that range. Well managed compost in the summer should be hovering between 120 and 130 degrees. Be careful: summer conditions can drive the temperature up very high, and at 160 degrees the microbes will die.

If you’re composting in the winter, it’s going to take longer. Winter temperatures in places like Colorado will slow things down quite a bit.

Oxygen and Moisture are Important

Moisture is important to support the composting process. Compost should be comparable to the wetness of a wrung-out sponge.

The compost should be uniformly moist, but not wet.

If the pile is too dry, materials will decompose very slowly. Add water during dry periods or when adding large amounts of brown organic material.

If the pile is too wet, turn the pile and mix the materials. Another option is to add dry, brown organic materials.

You also need air and water to penetrate to every layer. An aerating tool can help with this. Occasionally you’ll need to turn the entire mass.

Oxygen is needed to support the breakdown of plant material by bacteria. To supply oxygen, you will need to turn the compost pile so that materials at the edges are brought to the center of the pile. Turning the pile is important for complete composting and for controlling odor.

Nutrients are needed, too.

Nitrogen is critical, and low nitrogen will slow down the decomposition.

Green plant matter is higher in nitrogen then dry matter, and equal amounts of green and dry matter gives adequate nitrogen levels. If you don’t have enough green matter, nitrogen fertilizer helps.

How long does it take?

Wait at least two weeks before turning the pile, to allow the center of the pile to “heat up” and decompose. Once the pile has cooled in the center, decomposition of the materials has taken place. Frequent turning will help speed the composting process.

Bacteria and other microorganisms are the real workers in the compost process. By supplying organic materials, water, and oxygen, the already present bacteria will break down the plant material into useful compost for the garden. As the bacteria decompose the materials, they release heat, which is concentrated in the center of the pile.

You may also add layers of soil or finished compost to supply more bacteria and speed the composting process. Commercial starters are available but should not be necessary for compost piles that have a proper carbon to nitrogen ratio (1 part green organic material to 1 part brown organic material).

In addition to bacteria, larger organisms including insects and earthworms are active composters. These organisms break down large materials in the compost pile.

Using compost in the yard

Composting yard waste is not difficult, and it can improve the health of your garden, using material that was produced by your garden. Instead of throwing your valuable yard waste out, recycle it into nutrients that improve the soil and feed your plants.