Vermicomposting is the technical name for what is more commonly known as worm composting—the process of using various species of worms to digest and convert organic material into useable garden compost. Commercial vermicomposting bins are a convenient way to start turning your food scraps into compost for the garden, but there can be two problems with these ready-made bins. First, they are expensive, costing upward of $100 or more in many retail outlets. While they do work well, most gardeners would rather spend their money on plants.
Second, most commercial bins are also quite large, creating a space issue. Often, the most convenient place to store a worm bin is inside a kitchen cabinet—a place that is out of sight but still convenient for dumping food scraps. But kitchen cabinet space is usually at a premium and a large, tub-type bin takes up too much valuable space.
The solution to both the financial and space issues is to make your own worm bin. With just three plastic five-gallon buckets from your local home improvement store and a little time, you can start vermicomposting in an effective way.
Click Play to Learn How to Make Worm-Composting Bins
Before Getting Started
While any type of earthworm will gradually break down organic materials into useable compost, worm composting is best done with a type known as red wiggler worms (Eisenia fetida and E. andrei.) These species produce a considerably larger volume of digestive waste than do standard earthworms, they reproduce very quickly, and they tend to remain on the surface while feeding, which means that they quickly begin consuming new materials as they are added to the bin. Red wigglers also thrive at standard indoor room temperatures, making them ideal for indoor vermicomposting.
This DIY vermicomposting bin is structured so that the worms start out with bedding and food on one level. As that level is filled so the worms can digest it and turn it into vermicompost, you begin adding food and bedding to the next level. The worms instinctively migrate up into that level, leaving behind finished vermicompost for you to use in your garden. The ongoing practice involves switching back and forth between the two buckets, emptying finished compost then adding fresh food and bedding as the worms break it down for you.
The third bucket forms the bottom of the stack and is used to catch any moisture created as a byproduct from the other two bins. You can harvest this "vermicompost tea" from the lowest bucket and use it to fertilize your plants.
Equipment / Tools
- Drill with 3/16- and 1/8-inch twist bits
- 15 Plastic buckets (5-gallon size is best)
- 1 Bucket lid
- Shredded newspaper or cardboard
- 250 to 500 red wiggler composting worms
Drill Bottom Holes
In two of the buckets, drill 3/16-inch holes in the bottom, about 1 inch apart. Do not drill holes in the third bucket, which will serve as a catch basin to collect any moisture generated by the composting process.
Drill Side Holes
In both buckets that have bottom holes, also drill 1/8-inch-diameter holes about one inch apart through the top of the buckets around the entire circumference. This will provide aeration that will help break down the contents quickly.
Prepare the Lid
Drill a large number of 1/8-inch-diameter holes through the top of the lid. This, too, will provide added aeration that will help break down the contents quickly.
Assemble the Vermicomposting Bin
Stack one of the bins with drilled holes inside the catch-basin bucket without holes. Add 3 to 4 inches of moistened shredded newspaper or cardboard to this bucket, then add the worms. You can also add some food scraps at this time.
Cover the Bin
Now, put the lid on the bin and let the worms begin perform their natural function—digesting the refuse and turning it into nutritious compost.
Add food as often as you need to—whenever the contents have been mostly digested.
Add the Third Bucket
Once the contents of this layer have been partially digested by the worms, stack the next bucket with holes onto the top bin, adding fresh bedding and food to the new bucket and placing the lid on top. As they finish digesting the contents of the second bucket, the worms will start migrating up to the upper bucket for fresh food and bedding.
Harvest the Compost
As soon as most of the worms migrate up into the upper bucket, the contents of the intermediate bucket can be harvested. Vermicompost is a versatile material that makes a great soil amendment or mulch for virtually all plants.
The time it takes for the worms to break down the contents of the first bucket of bedding and scraps will depend on the number of worms and the quantity and type of organic material you put inside, but it generally takes three to six months to create a full bucket of compost ready for garden use. This might seem like a long time, but it can be considerably faster than passive composting in an open compost bin.
Don't let the contents get too wet. If they do, there are a number of ways to fix a wet worm bin, such as adding more fresh bedding. Don't let the contents dry out, either, as this is death for worms. The contents of the bin should just barely be moist, like a wrung-out sponge.
As the bottom bucket fills with liquid, this "compost tea" can be used to feed plants. Empty the bucket often, as it can begin to smell if allowed to remain too long.
Repeat the Process
As the intermediate bucket gets full and is emptied of its compost, move it to the top of the stack and begin filling it again.
Once established, your vermicomposting system can handle virtually all the organic non-animal refuse your house produces, including newspaper and cardboard.