Content on this page is generously provided by Joyce Jimerson, Master Composter/Recycler Program Manager
Composting in Whatcom County's Vermiculture
See also their Guide on creating a cheap and easy worm bin!
Kitchen wastes can be converted to a rich humus with the help of redworms. Children find worms fascinating. They are very well behaved "pets," and also help with household chores! The following is a guide to developing a home vermiculture or house worm box system.
What to Call It
The "home vermiculture system" or worm box system contains
Consider the needs of redworms and needs of the owner. Redworms need controlled
The container should be located in a place that is convenient for maintenance, but not in the way. A basement in colder climates or garage in warmer ones should have a moderate, consistent temperature.
Redworms should be protected from freezing temperatures. Temperatures below 50 degrees F. slow down worm activity.
What Kind & Size Container?
Worms With "The Right Stuff"
Redworms (Latin names and classifications):
This variety is the best redworm for home composting. They produce a large amount of compost in their natural habitats of leaves, manure, compost piles and in many other decaying organic materials. Redworms are on the market under many different common names. Some people call them "red wigglers," or "manure worms." Fishing suppliers may call them "red hybrid," "dungworm," or "striped worm." All these names are for the same kind of redworms.
This variety will adapt to the worm box environment, but they are really a soil earthworm. Their natural habitat is in soils which contain a lot of organic matter.
Worms NOT to use:
Redworms have babies!
Redworms are hermaphroditic or have both sexes in one body, but still must mate to create baby worms. If the worm has a swollen band, called the clitellum, at about one third between head and tail, this means that the worm is sexually mature. Redworms mate in their bedding at different levels, sometimes even on the surface. They may mate at any time of the year. They are attracted to each other (maybe for their beautiful body face, or other irresistible qualities.) They find each other and lie with their heads in opposite direction, bodies closely joined. They produce a secretion and secrete this through their clitella, a mucus that forms a band around each of them. Sperm from each worm move down a groove into receiving pouches of the other worm. The sperm enters in a storage sac. Some time after the worms have separated, the clitellum secretes another substance called albumin. This material forms a cocoon in which the eggs are fertilized and baby worms hatch.
Redworm cocoons are round shaped and small. They change color during their development, first white, becoming yellow, later brown. When new worms are ready to emerge, the cocoons are turning red. It takes at least three weeks for the worms to develop in the cocoon. Temperature and other conditions are factors in the development of the hatchlings. Although a cocoon might hold as many as 20 eggs, usually only 3 or 4 worms will emerge. The young hatchlings are whitish with a pink tinge showing their blood vessels.
Conditions that determine Redworm population:
If there is a lot of food available, worms will multiply at a high rate. If worms have to compete for food, the population will go down. If you want to increase the number of worms in your box, feed them more food, but also you may need a larger box for the greater numbers of worms. It's important to note that worm castings are toxic or poison to them, so you need to harvest the castings regularly.
How many worms to start with?
The number of redworms needed depends on the daily food waste. There is a worm to daily food ratio:
Or: one pound of worms can eat half a pound of food each day.
However, one pound of worms is as much as 1000 mature worms! New hatchlings are very small, and sometimes 150,000 are needed to make one pound.
Setting up a Worm System
Water: Bedding ration = 3:1 by weight.
If using dry bedding such as shredded paper, newspaper strips or cardboard, you need to wet it. One way is to put the material in a bucket and add water to it, until it is saturated--about a minute or two.
If using composted manures, it is more difficult to determine moisture. Be careful not to make the manure soggy! If the manure is too soggy, add some dry material to it, such as shredded paper cardboard or leaf mold. The goal is to keep your worm bin under aerobic rather than anaerobic conditions.
Moisture & Temperature:
A few drops of moisture released by squeezing could be a guideline for the right amount. If five or more drops are produced the material is too wet. The ideal temperature for worms is between 55 and 77 degrees Fahrenheit.
Adding worms to bedding:
When bedding is ready for the worms place the worms on top. They will disappear in a short time in the bedding. They don’t like light. By keeping some bright light close by the box the worms will disappear faster in the bedding. If some stay on the surface after some time, assume that they are unhealthy or maybe dead, and remove them.
Most kitchen waste or table scraps, any vegetables, grapefruits, orange rinds, apple peels, lettuce and cabbage, celery ends, spoiled food from the refrigerator, coffee grounds, tea bags, egg shells are all suitable worm meals.
Burying kitchen waste:
One way to manage a worm box is to pick a different spot to bury kitchen waste in the box. A 2’x2’ box has approximately nine locations where you can bury wastes. That gives you nine feedings before you have to repeat the cycle.
You need some air circulating in the box, or bad odors could occur.
Worms will usually like the earlier buried food wastes. They like decaying organic wastes best. They do not always wiggle to the newly added fresh food waste. They like the bacteria, fungi, and protozoa to break it down first! Worms help keep the decaying material aerobic and help keep conditions free of odors. They produce castings at the same time.
There are many other techniques for adding kitchen wastes, which vary with owner preference and the type of box or container. Some people may just have worms in a garbage can with holes drilled on the sides for aeration. Some bury this foot deep in the back yard, and worms can come in and out as conditions vary. They just throw the kitchen wastes on the surface. (Make sure you have a tight lid that is raccoon proof!) They may add some materials such as sand, soil or peat moss on top. Just be sure not to fill it too high with food and bedding, or it will pack down and may become anaerobic. Whatever works for the specific situation is fine—provided there are no odors or other problems.
Grind food waste?
Grinding food waste is extra work. These kitchen wastes break down in a very short time. Eggshells should be pulverized. Although redworms have very tiny mouths, and ground food would be easier for them, we want them to help us with kitchen waste! Too much time and energy spent preparing their food can be discouraging.
Overloading the system
The size of box and amount of worms are deciding factors for how much food should be put in the box. Remember the 2:1 ratio for worms. Two pounds of worms is needed for one pound of food per 24 hours. The surface area of the box should be 7 square feet if 7 pounds of waste in one week is consumed.
If too much kitchen waste is produced on certain occasions, the wastes could be temporarily stored in another container for use later. An overloaded worm box can become anaerobic, and stinky! If that happens, don’t add any fresh kitchen waste. If you leave it alone for a while, the situation will correct itself.
Do I need a worm sitter?
If you’re going on a vacation, you could feed the worms a little extra just before you leave. This is the best part of having worms as pets! Feed them and leave them undisturbed. This way, you can go away for weeks. If you leave for longer than 3 weeks, it might be good to have a worm loving friend come and feed them once.
Observe the worms
The less you disturb worms, the better off they are. However, you should make regular observations to know what is going on in the box. The best time to do this is at feeding time. Is the bedding still moist? Is the temperature inside the box between 55-77 degrees? Sometimes you find many worms at one spot in a feeding frenzy. Note what they like and don’t like. Look for worm eggs and baby worms. Are there any mating worms? Point out to children that worms don’t like to be touched or disturbed. They can’t tolerate bright light. A red light could be practical for observations of the worms.
Different foods for different worms
A worm's age can determine what food it likes to eat.
Harvesting castings and changing bedding
After weeks of adding food wastes the bedding goes down. This is a combination of worm activity and the microorganism activities. Decomposition and composting are taking place. The color of bedding becomes darker. The favorable environment for the worms decreases. The large amounts of castings might become harmful to the worms. Castings of one worm are toxic to another worm.
When to change the bedding depends on the bedding used, the quantity of the earthworms in the box, temperature and moisture conditions. Four to six months is a good guess for keeping the same bedding, if the worm boxes are correctly maintained.
Let the worms do the sorting
If you prefer only to add some new fresh bedding, carefully move the old bedding to one side of the box. Add the fresh bedding in the open space and start feeding in the new bedding.
Divide and dump technique
To divide the worms from the old bedding, dump the contents of the worm box on a sheet of plastic or a table. The worms will go down in the pile if you expose them to light. After a short time remove the top layer of the bedding up to the point you encounter worms. Wait a short time, and continue removing the bedding. You will end up with lots of worms in a small pile. If too many worms are left, some could be supplied for starting another box.
Frequently Asked Questions
Can they see?
No, worms don’t have eyes. However, they must have some kind of light sensor. They are very sensitive to bright light. They will try to hide as soon as exposed. It’s odd that anglers use a flashlight to catch night crawlers, since they retract in their burrows if you shine lights on them. Worms are less sensitive to red light. You can observe worms with red light. Placing a red cellophane between the light source and the worm box allows you to watch the worms.
Where is the mouth?
The worm’s mouth is in the first anterior segment. There is a small protruding lip just over the mouth, called prostomium. When the worm is foraging, this lip is stretching out. The prostomium is for sensing food.
Do they have teeth?
Worms have no teeth for chewing food.
How do they grind food?
Worms can only take small particles in their small mouths. Microorganisms soften the food before worms will eat it. Worms have a muscular gizzard. Small parts of food mixed with some grinding material such as sand, topsoil or limestone is ingested. The contractions from the muscles in the gizzard compress those particles against each other, mix it with fluid, and grind it to smaller pieces.
What happens to food once it leaves the gizzard?
The ground up food is mixed with enzymes in the worm’s intestine. This mixture breaks down the food, molecules pass through the intestine wall into the bloodstream for use where needed. Undigested material, including sand soil, bacterial and plant residues passes out of the worm as a worm casting.
If a worm is cut in to, will it grow back?
It depends on where the cut took place. If a worm is cut at the posterior end, sometimes a new tail will grow back on. Sometimes a second tail will appear next to a damaged tail. However, the posterior half of the worm can’t grow a new anterior (head.)
Do worms die in the box?
It’s hard to find dead worms in a worm box, but they do die in the box. Dead worm bodies decompose very quickly, because their bodies are between 75%-90% water. If you find many dead worms you should find out the cause. High heat (above 84 degrees) is fatal to them. Too much salt or acidic food waste can kill them. It’s best to change the bedding with fresh materials to solve the problem. Sometimes, partially replacing bedding may solve the problem.
How long do worms live?
Eisenia foetida can live for as long as four years, but often worms live and die in the same year. Conditions affect them such as dryness, or too hot or too cold weather.
Do worms need air?
Worms need oxygen to live. The oxygen diffuses across the moist tissue of their skin, from the region of greater concentration of oxygen (air) to that of lower concentration (inside the worm.) Carbon dioxide produced by the bodily processes of the worm also diffuses through skin. Moving from higher concentration to lesser concentration, carbon dioxide moves from the inside of the worm’s body out into the surrounding bedding. A constant supply of fresh air throughout the bedding helps this desirable exchange take place.