Vermicomposting: A Beginner’s Guide
Worm composting, or vermicomposting, is the transformation of organic waste using worms to create rich compost known as worm castings. Filled with vital nutrients and trace minerals, vermicompost is an excellent all around organic fertilizer and soil conditioner. Vermicompost is also a source of water soluble, slow-release nutrients for your garden, houseplants or lawn. Indoor vermicomposting is a convenient way of composting for apartment dwellers (and people who may not have the ability, space or resources) to maintain an outdoor container. Keep in mind that composting is a SIMPLE and natural process. Some newer systems simplify the endeavor and allow you to grow greens, herbs, and vegetables directly in your composting container. It is only complex as you want to make it. Just remember that… “Compost Happens!”.
(The Garden Tower 2 by Garden Tower Project)
Suggestions to get you started with either indoor or outdoor systems:
Worm composting containers come in many shapes and sizes. Worms will live anywhere their basic environmental conditions are met. If you are in the mood to DIY it, there are many creative homemade worm container designs and some from around the world are shown here. Some are simple and some rather elaborate. There is currently only one maker of systems that combine container gardening and vermicomposting in one single unit that can be used either indoors or out. Visit Garden Tower Project for more info on this particularly unique and productive system and see the resources below.
Things to consider in selecting a worm container:
Will the container be placed indoors or outdoors? Outdoor containers require a bit more consideration and maintenance than just a standard compost pile. Worms will double population approximately every three months.
- Site selection:
Select site for temperature stability. A garage, a shed or placed against a building work well in most areas North or South and for most systems, provide both winter protection and summer shade. Some systems will work equally well indoors and out, with temperature being one of the biggest factors affecting the system, other than: food supply, moisture and bedding. As is true in real estate, it’s all about… location, location, location!!!
Smaller containers are a bit trickier or more finicky than larger containers. In the event that there’s some kind of imbalance (temperature sensitivity, too much acid, moisture or anaerobic conditions) then there is no place for the worms to escape to. The compost containers like this DIY worm bin made out of plastic, although cheap, make your worms only a little harder to take care of than a pet rock.
The biggest challenges for the newbie worm wrangler:
- v Over feeding: This is *The* number one problem for beginning worm wranglers.
Remember: “too much of a good thing, is still too much of a good thing” and “Less is more” when choosing menu items for your squirms.
- v Moisture: Moisture can also become a big issue, More common with plastic
bins indoors caused by insufficient drainage. Bedding is one of the best answers for this situation. The other is aeration. Poke more holes above for air, below for drainage or turn and mix the pile to increase aeration. Add bedding to dry a container.
Whatever design you choose, remember the basics:
Bedding can make or break the farm. It provides plenty of carbon rich supplements. It helps soak up nitrogen rich acids and brings a good balance to the system. It also helps to hold in moisture and last but not least, increases your cocoon production (think baby squirms, Yea!).
When adding bedding to your composting containers think of materials that are spongy and porous like peat moss, straw, and corrugated cardboard (no glossy cardboard). We believe the browner (more organic) the cardboard is, the better it is for the worms.
If you want truly organic compost, Stay away from bleached/processed whites and don’t forget that you cannot add too much bedding. This keeps the container aerated and allows plenty of oxygen to flow throughout your worm composting containers.
- Keep your worms moist, not wet. The compost media should feel like a damp sponge wrung out, not soaking wet. This is an important rule of vermicomposting.
- Most of what are consider “greens”, are a good source of nitrogen. Add greens in moderate amounts to avoid highly acidic or high heat conditions.
You don’t need to add very much (or any water at all) to the system, depending on moisture content of your greens. Worm containers do not stink if properly taken care of. Scraps like broccoli, onions & cabbage have a strong odor, so you may need to limit their use. If you cover it sufficiently (with browns, bedding, wet paper, etc.) and leave it alone for a while, you can determine how much to put in each time and you will get a feel for how much they are eating.
What’s on the Menu?
Worms do not actually eat veggies. Worms exist on the (aerobic) bacteria that break down the food in the container. Food can be broken or cut up into 1” chunks. Smaller is better to increase surface area to benefit the bacteria and encourage good growth, which will help the process along.
Bedding eventually becomes food. The harder the Browns, the longer it takes for them to break down and become useable food or compost. Do not add more food if you see a lot of un-processed food.
Allow them time to work through the food they have before giving them more.
- Straw & Grasses • Kitchen scraps
- Leaves • Coffee, filters & Teabags
- Cardboard • Yard & garden waste
- Sawdust & Wood chips
Worms need Grit in their diet. This keeps them healthy and digesting well. Eggshells finely crushed or ground provide needed grit and are also helpful for reproduction (Babies again, Yea!) Diatomaceous Earth (DE) can be used for pest control for mites and also add some needed minerals and grit as well.
What not to add: Some items don’t belong in your compost pile. Hot compost piles will kill many diseases, weed seeds, and insects, the temperature does not get that high in vermicomposting and some of these nasty guests may survive to invade your garden. Certain materials can also invite unwanted critters to the pile or spread human diseases.
Avoid adding the following to your compost container:
- Kitchen scraps like meats, oils, fish, dairy products, and bones.
- Weeds that have gone to seed or that spread by their roots
- Diseased or insect-infested vegetable or flowers
- Herbicide-treated grass clippings or weeds
- Dog, cat, pig or human feces.
- Beware of pesticide laden fruits and vegetables
Types of worm containers –
There are many types from small to large scale (Resources below). A small scale, simple bin is basically a bucket or Tupperware container.
For a complete kit to hatch worm cocoons, and start a simple container inexpensively, check out the mini-bin at NLRworms at $24.95 This is a great starter kit for younger worm wranglers & educators.
For a container bigger than a breadbox, there is a larger municipal worm container for $49.95. Check out the Friendly Worm Habitat.
Beyond DIY Rubbermaid containers, things can get pricier. Flow Through containers are systems that are meant to be easily and harvested periodically or continuously.
The instructables version is similar to the Worm Inn ($69.00 does not include worms or stand) & Worm Inn Mega for $136.88 with corners for stand, no worms. $10-$20 of materials are needed to complete the stand)
The Worm Factory is $79.95 (+ $20 shiping). The basic kit is the three-tray version and the system can be expanded to seven trays. Stackable worm composting systems are popular because of their worms to space ratio. They hold a lot of composting worms and require very little space. These worm composting containers are designed to allow for the natural upward migration of the worms. Get more information on Flow Through designs here.
The Worm Factory 360 – $124.95 +$16.00 Shipping & Handling, comes with 4-trays and is expandable up to eight trays.
The Garden Tower Project has been building systems that are gardens with integrated vermicomposting for the past two years. They have recently introduced a highly refined, injection molded design that is available to early supporters of their Kickstarter effort for only $232 (delivered). The new system is easily accessible; it rotates 360 degrees, and is extremely water efficient and temperature tolerant. There is a drawer for compost tea collection as well as a baffle to allow compost to be emptied directly into the drawer. Visit Garden Tower Project. Available at this price only until December 7th
(Garden Tower user photos from around the USA)
Facebook: Vermicomposting – Wormfarming – Red Worm Composting – UncleJims
Educators: Please share your community\school projects on facebook at: GardenTeachersProject
Garden Tower project on Kickstarter: Find out about the new version at….
Garden Tower Project on Kickstarter or look at our original handmade version at www.GardenTowerProject.com and see lots of photos from happy supporters!