A question from Arlene:
Which is preferable as bedding: shredded newspaper, or straw? I have access to quite a bit of both.
This is an interesting question – and it provides me with a good opportunity to outline my overall bedding classification system (something touched on in the last podcast, and in the RWC Vermicomposting Guide).
I basically separate bedding materials into two broad categories – 1) Primary Bedding and 2) Secondary Bedding.
Primary Bedding – these are the materials that work great on their own or mixed with other (primary and/or secondard) bedding materials. They fulfill the two key requirements of a good quality bedding in that they hold water well, and they allow air flow. Some examples include shredded cardboard, shredded newsprint (and really, any bulky paper product) – and potentially even something like shredded clothes/sheets etc.
Secondary Bedding – these are the materials that tend to be lacking in at least one of the two “key requirements” mentioned above, so they should be mixed with other bedding materials for best results. Straw, fall leaves and wood chips are examples since they don’t hold water very well – but they DO allow air flow. Peat moss and coconut coir are also examples because they hold moisture really well, but are not great for air flow.
Gray Area – as is often the case in vermicomposting, there is definitely some gray area here! In the case of the straw and leaves (and similar materials), as they decompose they become more and more effective for moisture retention – not to mention taking on those “living material” properties that can be so beneficial. So rotten straw and leaves can actually end up being almost an “ultimate” bedding material. Same goes for really well-aged manure that had been originally mixed bulky materials (like straw).
Getting back to your question…
For a typical worm bin I’d definitely say that shredded newsprint is preferable as your main bedding – but straw can act as a great cover bedding if you don’t want a lid. Same goes for outdoor beds – straw is my favorite cover bedding (paper products and leaves are useless since they blow away).
Hope this helps!