Some materials have been marked as a caution, this is to highlight that they could cause problems with the composting process. They can be added to your compost bin but care needs to be taken with amounts with some materials e.g. leaves, grass cutting, animal manure and wood shavings. Perennial weeds can easily be pre treated before putting them directly into your compost bin. More information about the materials marked as a cautions can be found in our Can you compost it? Booklet.