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Stewardship Gardening

Backyard Composting

Part 2: How to make compost

Introduction

Part 1:
Composting basics

Part 2:
How to make compost

Part 3:
Health and safety questions

Part 4:
Using compost in your yard

Composting coffee grounds

Slow Composting

Employing slow composting is an easy and convenient way to turn yard wastes into a useful soil amendment. It is often the best method for people who do not have the time to tend a hot compost pile. Simply mix non-woody yard wastes into a pile and let them sit for a year or so. Microorganisms, insects, earthworms, and other decomposers will slowly break down the wastes. A mixture of energy materials and bulking agents provides the best food source and environment for decomposition.

Add fresh wastes to the pile by opening the pile, placing fresh wastes into the center, and covering them. This helps aerate the pile, and also buries the fresh wastes so they do not attract pests.

Fruit and vegetable wastes are particularly appealing to pests,. such as flies, rats and raccoons. To avoid pests, bury these wastes within the pile. If you bury the vegetable wastes in the pile, and pests are still a problem, you may need to screen the pile or keep vegetable wastes out.

You also can bury vegetable wastes directly in your garden. Dig a hole or a trench about a foot deep, add a few inches of vegetable wastes, mix them with the soil, and refill the trench with soil. Another way to avoid pests is to compost vegetable wastes in a worm bin.

Slow composting does not produce the heat needed to kill many weed seeds. It is best to pull and compost weeds before they go to seed. If you put seeds in the compost pile, be prepared for more weeding.

Fast Composting

If you create and maintain a balance of air, moisture, and energy for the compost microorganisms, they will produce a hot compost that will break down quickly and kill off many weed seeds and disease organisms. Making hot compost takes extra effort, but it produces a high quality product quickly.


Building the Pile

Step 1: Collect enough material to make a pile at least 1 cubic yard in volume (an open pile 5 feet wide at the base by3 feet high holds about a cubic yard). You need roughly two parts bulking agent to one part energy material (see table). Chop, shred, mow, or smash coarse materials so they will break down faster.

Step 2: Start the pile by adding energy material and bulking agent, and mixing with a pitchfork.

Step 3: Squeeze a handful of the mixed material to check its moisture level. If you can barely squeeze out a drop of water, the moisture level is ideal. If the pile is too dry, add water, and check the moisture again. If it is too wet, mix in some drier material.

Step 4. Continue adding energy material and bulking agent, mixing, and checking moisture until the pile is built.

Piles vs. Bins

You do not need a bin or other container to make compost.

Piles work well. Some people prefer containers because they look neater, or because it is easier to shield them from pests.

Containers can be simple or fancy. Make them from materials such as old pallets, lumber, mesh fencing, or cinder blocks. For hot compost, each bin should be about 3 feet by3 feet by 3 feet in size.

Avid composters often have three bins: two for turning, and one for curing compost

The King Co. Solid Waste Div. has an excellent fact sheet, " How to Choose a Compost Bin" that has some good tips.

Sometimes you may have several problems to overcome. If you cannot get the pile toheat, all is not lost, because the pile will still break down by the slow method.

Turning the Pile

Use a pitchfork to turn the pile weekly, and add water when needed. Turning gets air into the center of the pile and speeds the biological decay. Turning also mixes material from the outside of the pile into the hot center. Cover the pile during rainy periods so it will not get too wet.

Curing Phase

After initial mixing, a regularly turned pile usually stays hot (120'F to 150'F) for several weeks to a month. The pile will shrink to about half its original volume during the hot phase. The pile then needs to sit another for 4 to 8 weeks to cure. Temperatures during curing are 80'F to 110'F. The compost is ready to use when at least 8 weeks have passed since initial mixing, the pile no longer heats when turned, and the material looks dark and crumbly.

Curing affects the availability of nitrogen and the microbial activity of the compost. Uncured compost may harm some plants. This is most likely when compost is used in potting soil or to start seeds. Curing is less critical when small amounts of compost are worked into soil.

Questions and Answers

What if my compost isn't hot?

Check the pile.
  • If the pile is dry

it needs more moisture.
  • If the pile is mostly bulking agent,

it needs more nitrogen. Add energy materials or nitrogen fertilizer
  • If the pile is too wet,

add more bulking agent. Cover the pile or build a larger pile during the rainy season.
  • If the pile has a foul smell,

it needs more air and less water. Try turning the pile more often or adding more bulking agent.
  • If the pile is too small,

it will not hold the heat.

  • If it is cold outside

try building a larger pile to hold the heat.



To next partPart 3: Compost use, health and safety questions


Composting Backyard Composting Kitchen Waste Composting Livestock Manure Composting

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