“I have a query about castings. I have a tower bin system where the bottom bin has a tap and collects the worm tea. How should I be feeding the worms in order to be taking off the worm castings. Currently my bin looks more like compost and I do not see any worm castings. Is there a specific way in which to layer the bins in order to get a layer of castings? Please help!” ~ Jalda
It is interesting to see your differentiation between ‘compost’ and ‘castings’. In all honesty, if you are producing an end product that looks like a good compost you are definitely on the right track. As I discussed in this week’s main article, vermicomposts generally contain a high percentage of castings.
When the material is quite moist, it will be difficult to see the individual poop pellets (for lack of a more scientific term), but they are certainly there. Once the compost has dried out somewhat, the actual castings should be easier to see.
Let’s talk about a few steps you can take in order to produce a higher percentage of actual worm castings (essentially reviewing some of the things I mentioned earlier in the newsletter). Firstly, it will help a great deal if you can use bedding/food with a fairly consistent particle size – generally smaller particles will be processed more quickly and uniformly.
In other words, a material like peat moss might work better than big chunks of shredded cardboard, and food materials that are blended will produce better results than those left more intact. You do need to be careful with this approach however, since smaller particle size means less air-flow between the particles.
Using greater densities of worms will obviously also lead to increased production of castings. This combined with a longer retention time (eg before adding new trays and/or harvesting the material) might also allow you not to worry so much about particle size – i.e. given enough time and and a high enough density of worms, you can be sure that the vast majority of your bedding will be converted to castings.
Just generally optimizing conditions for the worms will also help increase their level of activity (thus resulting in increase castings production). They will need adequate warmth (cooler temps will slow down their metabolism), moisture and oxygen.
Anyway – hope this helps! Again, don’t ‘poo poo’ the compost – vermicompost can actually be more beneficial than pure worm castings in some situations (we’ll likely discuss this more next week).