Types of Worm Bins
When we talk about a worm bin we mean a home for you worms; what type of system will physically contain your worms
and bedding. The term "worm bin" is often used to describe one of many housing "systems" used to raise worms. In a
little while we will explain these different systems or bins.
Determining what type of worm bin, or system, you prefer is best done before ordering worms. But in reality most
beginning worm farmers come across something interesting online, or in a store and go with that. Quite often worms
are included in the package deal. Nothing wrong with that, in fact that's how we started.
There are several styles of worm bins so take the time to learn a bit more about them here. In selecting your worm
home / worm bin there are two very important considerations that need to be addressed. First choose
between a commercially manufactured worm bin or homemade
worm composting bins. Second; determine where you will keep your worms, in the house, or outside, or in a
sheltered building with no heating and cooling.
Traditional Worm Bin
The traditional worm bin is one of the oldest, and probably most common bin methods used raise worms. What to
use as a "bin" is only limited by your imagination. The most common bins these days are plastic Rubbermaid or
Sterilite storage containers. Other common containers modified to serve as worm bins are plastic buckets, kitty
litter containers, plastic restaurant tubs, or just about any other plastic container that has about a 2 gallon or
Bins generally have a cover to prevent worms from escaping. Worm farmers often modify their bins with
vents to allow for ventilation. Drainage holes and spigots are also frequently added to drain off
moisture, which makes harvesting easier.
The plastic bin is not high tech; yet many commercial worm farming operations use the humble worm bin by
the hundreds. Worm bins are inexpensive and easy to make, however they do have drawbacks. They can get heavy,
water logged, and are more difficult to harvest worms and worm castings from. Learn more about traditional worm
bins on our bin page.
Large worm bins are often kept outdoors year round; however in both very cold and very hot
climates temperature must be controlled.
Flow Through Worm Bin Systems
The flow through worm bin was designed to address some of the shortcomings and problems of traditional
worm bins by taking advantage of the red worms natural instincts to live near the surface of the earth. In this
system food and worms are litterally added to the top of the bin and worm casting, worm poop, is
harvested from the bottom.
Typical flow through systems are constructed from a wooden box, plastic barrels, or metal drums. The bottom of
the bin is left open. A network of pipes, wires, or dowels runs horizontally across the bottom of the
bin, just above the opening. A layer of cardboard or paper is placed on top of the network preventing the
bedding and worms from falling through. Food is added from the top and once converted to castings is harvested
from the bottom.
Flow through systems are becoming more and more popular since they make worm farming much easier; particularly
when harvesting castings. Flow through systems are commercially produced. However may are home made and constructed
from plans, or engineered and built by worm farmers themselves. Learn more about flow through worm bins on our flow
through worm bin page.
Stacked Bin Worm Bin Systems
Stacked worm bin systems were designed to save space by utilizing a series of worm bins, or trays, stacked upon one
another vertically with the entire stack sitting securely on a base unit that doubles as a moisture collector.
Stacked bin systems have numerous holes in the bottom of each bin that allow worms to "migrate" up to the next
bin once the bedding and food in the first tray is converted to castings.
Most of the worms crawl up out of the bottom bins making harvesting of worm castings easier than in a
traditional bin. Since the trays are nestled upon one another and are topped off with a tight fitting lid moisture
retention is excellent. The base of the system usually has a drain or spigot allowing for easy drainage of
liquid and collection of worm tea.
There are many excellent commercially produced stacking worm bin systems on the market. However a nice system can
cost anywhere from $50.00 to $100.00. For those handy with tools a homemade stacking system can be constructed from
wood, plastic bins, or kitty litter buckets. For more information on stacked worm bins see our stacking worm bin
Worm trays are very similar to worm bins; in fact you could almost classify worm trays as shallow bins. However
worm trays are generally utilized a bit differently than the traditional bin. Worm trays are often used by
commercial worm farmers, or people looking to breed serious numbers of worms. Commercial worm farmers may use
hundreds of trays to breed worms.
The use of worm trays will produce worm castings; but typically the focus of using worm trays is
using them for reproducing worms in a very controlled and well thought out system. In these systems worms are fed a
very controlled diet, spend only enough time in the trays to produce cocoons, then are harvested and
moved on to another set of bins to start the process over. Or they are sold. The bedding is then set aside for
the cocoons to hatch; thus starting a new tray of worms.
OutDoor Worm Bins
Maintaining an outdoor bin means different things to different worm farmers. Outdoor bins come in many styles.
An above ground out door worm bin is typically a large bin or flow through system that is insulated or temperature
controlled to maintain survivable conditions for worms year round. These types of systems depend on the insulation
and heat naturally created during the composting process.
In ground systems include windrows, vermitrenches, and buried bins. As the name "in
ground" implies the entire system of worms, bedding, and food are all contained in the
A buried bin is just that. A bid in buried flush with the ground and functions as a contained system. As long as
the proper conditions and food are maintained the worms will not escape.
Windrows, sometimes called vermitrenches, are long straight trenches cut into the earth. The trenches are filled
with a bedding and food material. Aged horse manure, shredded cardboard, and decomposing vegetables are layered
into the trench. Once the worms are added more bedding is added on top of them. In the winter an insulating layer
of leaves or straw is piled atop the trenches. Again, the insulating material and heat of decomposition maintains a
temperature that allows the worms to survive.
Back to the top of the worm bin page.