Question from Robin:
My worm farm is about four mo old. Is there a point where I have to start removing some of the composted stuff, or is ok to leave in the bin as long as there is always also plenty of uncomposted straw and food scraps for them to eat? Thank you.
I would say that the 4-6 month mark is when you should definitely start to think about harvesting material from your vermicomposting system, or even performing a major overhaul. By this point the habitat quality will likely be on the decline – as more and more vermicompost accumulates – even if there is a fair amount of unfinished material..
Continuing to add food to a habitat that is mostly vermicompost can lead to what I’ve referred to in the past as “Mature Worm Bin Syndrome”. You may find that – one day, out of the blue – your worms suddenly seem intent on escaping, and/or they actually start to die off.
That being said, adding lots of good bedding all the way along (something I think a lot of people forget to do), and scooping out vermicompost periodically from the lower reaches of the system will likely extend the life of the system (potentially by quite a lot in fact – it’s not unheard of to keep a regular tub system going for more than a year). But for best results you may simply want to completely separate the worms from the vermicompost and start fresh OR – if you have room, and an interest in expanding – “split your bin” to create two new systems.
NOTE: Any sort of flow-through system (eg. Worm Inn, vertical migration stacking bins etc) will naturally have a much longer “life”, since the vermicompost is (hopefully) being removed continually over time.