Over the past 21 years I have been asked, many times, how quickly a worm bin will double the number of worms normally? Here is a brief on this topic. The other title for this is: Population Growth Rates for Red Wigglers.
Under favorable conditions your Eisenia fetida worm population will multiply rapidly. A mature wiggler (three months old) can produce two to three cocoons per week. Each cocoon averages three hatchlings.
> Cocoons take up to 11 weeks to mature and hatch.
> Hatchlings require 2-3 months more before they grow to be mature breeding worms.
Population productivity over 11 week incubation period:
1 worm x 3 cocoons/wk x 3 hatchlings/cocoon= 9 hatchlings/wk
11 weeks x 9 hatchlings/wk = 99 hatchlings/worm
In 2 to 3 months those hatchlings will be mature breeders, producing offspring of their own. At the same time their parents are continuing to mate and create offspring.
As conditions in the bin become crowded, the adult worms will try to leave the bin rather than compete with the young for food.
Population increase is a good reason to harvest the bin every 4 to 6 months. As I have mentioned here before, one of the cardinal signs that the bin is ready to be harvested is that all the worms will begin to congregate, at or around the top of your bin. Because they have nowhere else to go and are virtually trapped. This sign or reason and the other most important sign(s): all the organic food waste and bedding has been consumed by the worms. I have also wrote that it is a good idea to have a worm annex handy. This is another bin (or bin like container, pre-drilled) you have handy. You can restart the bin ASAP for the worms need of a new home with one of these. An annex is always a good idea to have just in case you do go out to feed the worms and they have all started to be massing around the lid of their bin. Here is a sure sign you need to evaluate your bin and take action. Harvesting your bin has been covered in a previous post in two different ways. I am sure you will find the way that suits your specific needs and time constraints.
> Red worms will multiply faster than you think. Especially if your bin conditions are just right.
> You might consider marking your calendar when you start your bin and make notes on it about how it looks condition-wise for harvesting.
> Another item in your bin to be on the look out for are the hatchlings and cocoons and their stages of development. This will tip you off to the population growth rate of your bin.
Until I am back I hope you are enjoying your bin and learning from your worms.