Can I put moss in my composter


This is an interesting question, and the answer is yes, but ideally not in huge quantities.  The City of Toronto refers to peat moss being compostable, but I assume you are referring to the compact green moss that we find in our lawns in shady areas.   Some experts note that large quantities of wet moss will form a slimy layer in the compost bin, as you would find with a large quantity of wet grass. They also note that moss is very dense, and will take a long time to decompose.