How to Make Worm Compost in Three Easy Steps
Learn How to Make Vermicompost
This step-by-step guide includes short biology of worms and three easy steps to maintaining a worm bin. You'll learn everything you need to know about buying worms, feeding them, harvesting the vermicompost, and using the finished product.
Read on to learn all about making vermicompost!
An Introduction to Keeping a Worm Bin
Convert those Food Scraps into Nutrient-Rich Compost. A worm bin is more than an indoor composter—it’s an educational microcosm for adults and children. Not only will a worm bin provide the most luscious crumbly black gold, it also entertains. With the growing popularity of worm castings and worm casting-enriched products, there are many reasons for, and benefits from, doing it yourself. Not only will your worm bin cut-down on your household’s organic waste, it is also a great way to make moisture-retentive, microorganism and nutrient-rich compost, even if there’s no space to maintain a compost pile. And it’s easy! I promise and I’ll show you, but first a little background.
Simple Worm Biology
The two species of manure worms which are most commonly used for vermicomposting are Eisenia foetida and Lumbricus rubellus. They are particularly skilled at producing vermicompost because they normally live in piles of decaying organic matter where other worms can't survive. Lumbricus rubellus will eventually out-breed and overtake the Eisenia foetidas, so it's best to choose one or the other, rather than a mixture.
Worms hatch two or three at a time from tiny egg sacs called cocoons. Although they are roughly the size of a pin head, the cocoons are rugged and capable of surviving extremely adverse conditions. The cocoons are made from the clitellum, the thickened band around the worm. Although worms are hermaphrodites, they do not reproduce individually. When worms mate, they use their own eggs and exchange sperm with the other worm. The eggs are deposited into the clitellum. Then the clitellum slips off, leaving a tightly sealed balloon that hatches anywhere from 14–45 days, depending on soil temperature. The baby worms emerge from the sac as colorless threads without sex organs. Within six weeks the baby worms fully mature.
Since worms do not have teeth, they must wait for the food to become moldy before slurping the mold off the surface. Worms chew their food in a gizzard—they need stones or eggshells to help grind the food.
Coco Coir Bedding Materials
Step 1: Buying Worms and a Worm Bin
Like anything, you can spend as much as you want on a worm bin setup. Pre-manufactured, multi-tiered worm bins are offered by several brands, but a suitable home can be made from a plastic Rubbermaid storage tote for less than ten dollars. A twelve-gallon storage tote is ample for one to two pounds of worms. Red Wigglers, Eisenia foetida, are readily available from many online sources. They usually cost about $25 a pound.
Drill air holes in the sides and lid of your storage tote, then add the bedding material. Newspaper is a very popular choice because it is plentiful and also grows mold, which the worms will digest. Shred newspapers into one-inch strips and soak in tap water. Thoroughly wring it out and fluff it up before adding to the bin. Cornmeal is a favorite worm food that can be added to brand new setups to help the worms get acclimated.
Many worm owners prefer adding shredded coconut fibers, coir, or sterile, compressed soil. I believe a blend of coir and newspaper is best.
It's an excellent idea to set up your bind before your worms arrive. When worms are added to the bin, they can feel threatened and plan a grand escape. This can be managed by placing a bright light near the bin for the first few days. If you worms try to escape regularly, it could indicate underlying problems with conditions inside, such as too much moisture, not enough moisture, etc.
Step 2: Feeding the Worms
One pound of worms can consume a maximum of eight ounces of food per day. If the bin is full of food scraps, additional material may be saved in the freezer and used later. Freezing also kills pesky fly larvae. Worms will eat all fruits and vegetables except citrus. Worms can also consume natural fibers, like dryer lint, worn out socks or jeans. It will just take awhile. Things that should not be added include onions, meat, and dairy.
One of the most popular ways of feeding is the pocket method, which means the day's scraps are deposited in one small “pocket” and covered with bedding. Always cover food scraps with bedding to cut down on fruit flies, fungus gnats and odor. One of the best reasons for pocket feeding is the entire bin is not disturbed at once. If the worms' habitat is disturbed, they will feel threatened and look for a safer place to go by escaping from the bin. One of the fascinating things about the worms is they will adapt to the conditions in your bin. For example, if a filter of coffee grounds is added to the bin every day, eventually the subsequent generations will consume more coffee grounds than the worms who were not accustomed to that food.
Commercial Worm Bins
These engineered worm bins are designed to maximize your worm composting results year round.
Step 3: Harvesting and Using Castings
A bin containing one pound of worms in a two-person household may yield approximately fifteen pounds of finished worm castings, or vermicompost, in a year. There are several ways to harvest the vermicompost. The idea is to let the remaining eggs hatch before removing the castings from the bin. An effective way is to separate the finished vermicompost from the active feeding area, so the hatchlings are forced to migrate to the food.
Finished and partially finished vermicompost can be used in several ways. It can be added to potting soil, potted plants, garden beds, or used to make "worm tea," a mixture of castings and water.
Worm tea is very easy to brew. Fill a one-quart container with water. Add a small amount of worm castings, up to one tablespoon. Add an equal amount of sugar source for the microorganisms to consume, so they will multiply. Molasses, which is a microorganism supplement on its own, is great for this. When the tea no longer smells like molasses, the microorganisms have consumed the sugar source and the worm tea is ready. Fruit juice, feed hay, or cornmeal can also be used as sugar sources. Kelp, comfrey, alfalfa and anything else that is beneficial can also be added. It can take anywhere from 4-24 hours depending on the temperature. Always leave the container uncovered and stir the water several times to add oxygen.
Controlling the moisture can be tricky, especially in new setups where the worms are living in nearly 100% bedding. Your bin can go from water-logged to parched in no time. The key is to balance moisture levels. Both problems can be corrected by adding more newspaper. It the bin becomes dry, add wet newspaper. If it is wet, mix in some dry bedding and crack the cover, but be careful, this can dry out the bin very rapidly.
Leachate, anaerobic water from the bottom of the bin, is sometimes sold as worm tea. Leachate is a purported phytotoxin and should not be applied to plants. A healthy bin with the proper moisture balance will not collect leachate. Typically a worm bin smells less than a garbage can. If there is excessive odor detectable outside the bin, try adding extra bedding, or breaking up pockets of anaerobic material in the bottom of the bin.
In many ways, worms are ideal pets. They don’t make noise. They don’t require a lot of care or attention. It’s simple and cheap to set up a worm bin. They stay in their bin when their owners go on vacation. And, of course, they make nutritious compost. As you get familiar with your worms, you’ll see them differently--more like pets. They are tame, cute worms, not gross outside worms. They work with you to create microorganism-rich vermicompost that your plants will love.
Worms Eat My Garbage: A Must-Read Book on Vermicomposting
This comprehensive book and complete guide to worm composting is ideal for anyone interested in the subject. The 162-page book covers everything you need to now. Learn about the sex life of a worm, how to prepare bedding, how to set up and maintain a small-scale worm farm.
- Worm Composting Bins | What is the best Wormery?
Commercial vermicompost options and plans for building a Rubbermaid Worm Bin
- Worm-bin construction made simple | Rodale Institute
Kelly Grube of the Rodale Institute shares information about building and maintaining a worm bin.
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This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
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