By the end of this lesson: you will choose materials based on structure, cleanliness and availability.

Brown corrugated cardboard is one of the most useful materials available. It absorbs moisture, creates structure and is normally easy to source. Remove plastic tape, glossy coatings and heavily contaminated sections. Shred or tear it so it mixes through the system rather than forming flat waterproof layers.

Paper egg boxes and plain paper can be useful, although office paper can (and usually does) mat if used alone. Coir holds moisture well and is convenient, but it can become dense and it costs money. Leaf mould and mature compost bring microbial life but may introduce insects, seeds or unwanted material.

Do not use fresh manure, chemically treated wood products, glossy paper, heavily inked packaging or anything with a strong chemical smell. When uncertain, leave it out.

Top Tip – Worms are cheaper to feed than they are to replace.