DIY Worm Compost Bin

Worm compost, also known as Black Gold, is a gardenista’s (or gardener’s) dream for any garden - it’s richer in nutrients and trace elements than most soils you find on the shelf of your local garden center and organic.

Before even thinking about touching worms or what you’re going to do with the Black Gold that you’re going to get from composting, it’s super important to create the best home for your worms! Sure you can find fancy worm factories online for $100 or more, but we’re going to explore how to build a Worm Compost bin on a shoestring budget and in less than two hours.     

Worm House Tools & Materials 

As with any project, it’s best to collect all the tools and materials before you start.  Two dark plastic bins (2 - 18 gallons) will be needed to contain the worms. I emphasize dark bins, because worms do not like light.  The two bins will need extra space between them to maximize air flow, so spacers of some kind (wine corks, stones, bricks) are needed.  A drill, screens for the holes, waterproof glue/duct tape, and clean sand or organic soil will also be needed.  The complete list of the tools and materials needed to build your worms a home is below.   

Tools & Materials: 

  •     (2) Dark Plastic bins (18 gallons bins are recommended by UF/IFAS and EPA)

  •     Spacers: wine corks, stones, bricks (keep weight in mind)

  •     Shredded newspaper, cardboard, paper, yard waste

  •     Drill 

  •     Screen for holes

  •     Waterproof Glue or duct tape

  •     Clean sand/ organic soil

Worm Bedding

Shredded newspaper, cardboard, paper, and dry brown yard waste are all great options for worm bedding.  It is recommended that you collect, shred, and/or cut up this material ahead of time before picking up your worm buddies and/or assembling your bin.  The bedding needs to be damp, like a wrung out sponge, before placing in the bin. It’s easier to get the bedding damp before placing into the bin. One way to achieve this is by soaking the paper and cardboard in water overnight or for a few hours. Then wring out the excess moisture. Too much moisture is not a good thing as worms breath through their skin and problematic conditions can arise.

Note: Be sure not to include colored ink, shipping labels, or stickers. Colored ink can be toxic to worms and shipping labels or stickers will not breakdown in the timeframe you need to make compost for your garden.

Ideal Worm Bedding Materials:

  • Shredded newspaper (black & white only)

  • Shredded cardboard

  • Shredded paper (black and white only)

  • Grass clippings

  • Brown/decaying leaves

Side Note: The bedding doesn’t need to be the same size or shape.  Different shapes and sizes create air pockets, allowing better ventilation or air flow for the worm bin.  

Build It

So you have all your tools, bin materials, and worm bedding; it’s time to build the worms a place to eat microbes and make some Black Gold! 

  • Grab just one of your plastic bins, the drill and either a ¼ or ⅛ drill bit.

  • Drill holes (1-2) inches below the top of the bin along the longer sides every few (1-2) inches in a straight line.

  • Drill holes underneath the bin lengthwise every few (2-3) inches along both bottom sides in a straight line, offset 2-3 inches from both sides. This is to allow any accumulated water or moisture (compost tea) to drain. 

  • This step only needs to be done with one, not both of the plastic bins to promote oxygen flow between them.  

Next, you need to keep the worms from escaping! 

  • Cut the screen material just large enough to cover the holes.  Think strips.

  • Using the waterproof glue or duct tape secure the screen into place on the inside of the plastic bin to cover the holes that were drilled.

  • Allow to dry.

Side Note: It is super important to make sure the screen is secure at this step!  Making sure your screen is secure at this step will minimize future issues.

The two plastic bins will need to be separated by spacers to promote airflow and sufficient oxygen within the bin.  Various materials, such as wine corks, rocks, bricks, can be used to create more space between the bins.  I recommend that you keep the weight of the bins in mind when choosing the spacers. The heavier the bin, the more difficult it will be to move later on.    

Welcome Home Party

  • Once the worm compost bin is assembled, add damp worm bedding for the bottom layer.

  • Then kitchen scraps.

  • Add worm buddies. (Do some research to find worms based on your area. Recommend Red Wigglers for Florida Homeowners/Gardenistas/Gardeners

  • Top with a loose thin layer of bedding.

  • Close the lid, and keep the bin in a dark temperature controlled area. 

For the first few days, keep an eye around the bin’s holes for attempted escapees. It’s easier to fix loose screens early on before the kitchen and yard waste starts really decomposing.  

When content, the worms will be more likely to mate and double the population. Keeping your worms happy with ideal conditions will maximize how much Black Gold your worms make.

Want to Learn More?

Keep an eye out for future Florida Gardenista posts, blogs, and videos on wormy stuff!  I will be releasing more info on Worm Composting soon such as what to feed your worms, tips to sustain your worm bin, and how to harvest your worm compost after three months.

Questions? Check out my other blog posts to see if I have answers for you there. If not, I’d love to hear from you! Click the Contact link to send me a message or leave a comment.         

Kristy Buchler