Choosing Your Worm Bin

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One of the first things to consider when starting or expanding your worm farm is "What type of worm bin should I use?" Sometimes what seems like a quick answer can actually turn into a much more thoughtful decision than we imagined.

To answer this question, lets start by thinking "outside the bin" first. This will require you to look at your situation and make a decision that will be unique to you. In other words, there is no right or wrong bin, only the right one for you.

"Limited space creates unlimited creativity"  

Whether you build your own, or purchase a pre-made bin, it is likely they will fall into one of the three categories:

  • Bulk Bins
  • Flow Through Bins
  • Stackable Bins

‌Bulk Bins

The bulk bin's only limitation is our creativity. They can be made out of virtually anything that can hold soil volume. This could be 5 gallon buckets, plastic totes, plastic trays, garbage cans, etc. I've even seen people make bins out of old refrigerators, beds, and bathtubs. Actually it doesn't even need a bin to be a bulk bin, it could simply be a large mound.

When creating your bulk bins, keep in mind that the two major things required are oxygen and drainage. I have chosen to not use lids on any of my bulk bins so that i never have a problem with oxygen. Instead i use a breathable dark fabric and light to keep worms in the bins. If you decide to use lids, just drill plenty of holes in your bin so oxygen can flow through. The greater the surface area of your bin, the greater the airflow will be.

Drainage can be controlled in a couple different ways. If your bins are for the exterior or another surface where cleanliness is not important, you can simply drill some holes in the bottom of your bin so any excess moisture can work its way out. If you are working in a space that you would like to keep a little cleaner, a tray could be placed under the bin with holes to catch the excess moisture. Gravity will work its magic when it comes to excess moisture, so simply find a way to let it escape.


  • Affordability
  • Variety of materials
  • Variety of sizes
  • Versatility  


  • Aeration can be challenging with lids
  • Drainage can be messy
  • Can be labor intensive

Craft_Castings | Instagram

Smaller bulk bins can require a lot of maintenance and management. You will want to check your bins on a regular basis to ensure the conditions are correct. However, bulk bins make it easy to maintain different breeds of worms. Also, in the event of a catastrophe and your bin has anaerobic conditions, your risk is mitigated to only that bin.

"There are never worming mistakes, only experiments"

Flow Through Bins

I've always loved the continuous flow bins for my gardens. They are kind of like an investment that pays dividends. As a gardener, I don't need all the castings from a bin at once. I want a "flow" of castings that can be harvested in small amounts throughout the season. I believe that the smaller vertical style CFT bins may be one of the best solutions for gardeners.

Continuous flow systems can be purchased or they can be a great DIY project. Some of the most common small CFT bins that are available to purchase are the

I've used and sold the Urban Worm Bag to local customers - and my son has a couple Vermibags of different sizes and he is very happy with them.

Along with using these smaller systems, I have also built my own large CFT bins so that I could make them custom sizes to fit my space [View CFT Building Videos]

Composting worms live primarily in the top view inches of the surface where the majority of the food and oxygen is. Food is added to the top of the bin, and castings are harvested from the bottom. Because of this dynamic, when the castings are harvested they are usually free of worms (especially using red wigglers)


  • Very Efficient
  • Great Oxygen Flow
  • Easy Harvesting
  • Built in Drainage


  • More Expensive
  • Not as Portable

bamaMark |

The same system can also work horizontally if you have the space outdoors and are in a suitable climate. You would simply create a pile of bedding, and feed on one side of the pile. This will ensure the worms will be continually migrating to the side that is being fed. The backside of this pile can be harvested for castings. This is also known as a "Wedge CFT System" ‌
‌ ‌

"Information is like Compost, It does no good unless we spread it around" - Eliot Coleman

Stackable Bins

The Stackable bins are like the Condo's of the Worm World.  They are clean and small which makes them a great choice when space is limited. Its like a cleaner way of worming compared to the CFT system because all of the bedding and castings will stay in 4 or so trays that are stacked on top of each other. As your worms eat the food and organic matter in the bottom tray, they will naturally move upward to the next tray with the food. Once they reach the top, you can harvest the castings out of the bottom tray and replenish with fresh bedding and food. As you can imagine, The cycle never ends!

The most popular stackable worm bins are

If you like to work with your hands, It could also be a great DIY project!


  • Availability
  • Ease of Harvesting
  • Fits in small spaces
  • Great Oxygen Flow


  • Price
  • Small production
Conall | Flickr

For these tray systems, surface area of your worm bin is more important than depth because common composting worms live in the top few inches. Stackable worm bins really do a great job at maximizing the surface area.

"Start from wherever you are,
and with whatever you've got" - Jim Rohn

In Summary

Sometimes the search for perfection can be our biggest hindrance to growth. The answers seem to be so close, why can't someone just tell us whats best for us?! But in reality, there are a lot of questions that maybe shouldn't be answered, only guided through & experienced. In a weird way, struggle and failure can create community and wisdom.  The "answers" we find will be modest in comparison to the value of the journey and the connections we make.

When you find a bin that suits your needs, I want to encourage you to take action. We all have a lot to learn about the simple worm. Once you start, you will figure it out. We dont need a handful of worm farmers worming perfectly, we need a million worm farmers doing it imperfectly. And of course, sharing their failures & successes with each other :)

Have a wonderful worm week! ‌