Composting With Worms

Part 1: Worm box basics

Introduction

Part 1:
Worm box basics

Part 2:
Worm box management

Part 3:
Commonly asked questions

More worm composting information

Composting coffee grounds

Stewardship gardening links
outside WSU

Where To Place A Worm Box

Put the worm box where the temperature and the moisture can be controlled. An ideal temperature range for composting worms is from 70-90 F.

Worms also need a moist environment. Air circulation is a must in and around the worm box.

Chose an aesthetic location that is convenient for maintaining the box.

Worm Box Size

The size depends on the average pounds of wastes per week. A box measuring 1' by 2' by 3' can handle 6 pounds of kitchen wastes per week, which is the average for a family of 4 to 6 persons. One pound of worms is recommended for this amount of wastes.

Starting A Worm Box

Usually wooden boxes made of plywood are used. If you are using a plastic bin, be sure to add both drainage and aeration holes. Never use a container which has been used for storing toxic chemicals. Start by putting bedding in the worm box. Corrugated cardboard, news-print and newspapers shredded in strips four inches long by 1 inch wide make excellent bedding.

The worms need some grit for breaking down their food. Add a little topsoil for this purpose. Put the worms on top of the bedding.

Moisture

The worm's body and the bedding should have the same amount of moisture content. In order to survive, worms require 75% to 90% moisture content.

To achieve this percentage, add three pounds of water for each pound of dry bedding, that is a ratio of 3:1.

An easy way to check the moisture content of your bedding is to squeeze some in your hand. If a few drops of moisture are released by squeezing the bedding, the bedding is sufficiently moist. If five or more drops are produced the bedding is likely too wet.

What Kind Of Worms Do I Use?

There are two varieties of red worms which adapt to a box environment.

1. Red worm (Lumbricus rubellus)
2. Red worm (Eisinia foetida)

These red worms feed on the surface of organic matter.

Red worms rapidly convert kitchen waste into usable compost.

What Kind Of Worms Should Not Be Used?

Nightcrawlers and other garden earthworms are very important for soil improvement, but won't survive in a worm box. Earthworms only live in furrows in the soil.

How Many Worms Are Needed?

The amount of worms required in a box depends on the daily weight of food waste to be disposed of. Since worms can eat their own weight in food in 24 hours, worm weight is used instead of number.

2 pounds of worms are required for each pound of kitchen waste, that is a ratio of 2:1.

For example: if you produce 3.5 pounds of kitchen waste per week, you should use one pound of worms.

Since you require two pounds of worms for each pound of daily waste, you need one pound of worms in your box.

Red Worm Sources

• Check with the Master Recycler Composters or Master Gardeners at your local WSU Extension Office.
• The Tilth Organization in Seattle.

Part 2: Worm box management

More information about this topic is available through your local WSU Extension Office