After studying worms in nature in some manure and leaf compost piles for a while I began to notice something. Both piles compacted over time from sitting, rain… When the weather was wet, you could find worms throughout the piles. During dryer weeks, the piles dried out and the worms would congregate towards the bottom.
Now while many parts of the country are inundated with rains and flooding, here in the southeast we are dry and hot. The manure pile at times has dried out so much; the worms could not be found in the manure itself but rather moved into the ground under the pile which helps to retain a little moisture there.
Getting to my point here, if you look at worms in the ground, there are no holes in the bottom for air to pass through as many, including myself (which I still smack the back of my head from time to time for doing so) state you need air holes on the bottom of your worm bins when raising worms. Others will say it is for water to drain through or both.
Here is what I did. I setup two identical buckets without any holes on the bottom, however numerous air holes around the top as well as set them in a well ventilated area.
I placed enough moisture and food mixture in both to sustain ½ pound of red wigglers in each. They both contained 2.5 gallons of bedding / food mixture.
The only difference was the bedding material by which one was sphagnum peat moss while the other contained coconut coir, one which has been aged for at least 18 months and rinsed completely.
After 30 days I opened the two buckets screened the materials and found just about ¾ of a pound of worms in each. This was not due to additional worms but rather the increased size of the worms and their individual weights.
While both appeared at first to work the same, I found the coconut coir had a smell, started turning anaerobic in the bottom half of the bucket while the bucket containing the peat moss smelled like fresh earth throughout. The issue came down to the coconut coir not holding water as well and draining so that the bottom was much moister than the top.
The other difference in this setup was that there was right about a 10% higher cocoon rate in the peat moss bucket.
These were just a couple things we noticed, however onto the reason for this article again.
The worms not only fared well without any holes for aeration but grew in size, hence a happy environment for them.
I then proceeded to build a new stack unit; this permits me to hold a good number of worms for breeding, hatching and growing worms in less square footage of floor area. The bins, which are small, cement mixing tubs which when filled to an inch from the top, give me right about 1 cubic foot of bedding and food materials. None of the bins have any holes drilled on the bottom.
Now we have used these for going on two months now with all four types of worms we raise here, red wigglers, African nightcrawlers, European nightcrawlers and Alabama Jumpers, hence why the different color tags on each.
From growing, breeding, hatching and using as holding bins, there have not been any issues.
It appears the worms, just as in the case of the manure pile when it is moist, thrive very well, theoretically perhaps due to the increased aeration over the open bedding surface. By placing a piece of burlap over the top of the bedding and keeping it damp helps to keep the top from drying as quickly while still allowing good breath ability for the worms.
In short, unless you are over watering or feeding a load of vegetable scraps such as melons releasing lots of moisture, worms do not need holes on the bottom of their worm bins and actually appear to grow faster when in a more natural environment, allowing the bottom to stay moist and only needing a little spray of water on top.
I will be writing about other facts we have found in our tests the past several months including a way to assist in preventing many pests from either inhabiting your worm bin or at least keeping the numbers under control so as they do not get out of control!