I'd also avoid hemlock it can be toxic to humans who knows what a snake would react. http://www.woodweb.com/knowledge_bas...the_Woods.html

I am in Canada and cyprus mulch is only available thru pet stores and is horrendously expensive. Additionally it is in places threatened and placed on threatened lists it seems a sin to me to use cyprus that is critical to the everglades for my snakes.

Coco products will hold humidity very well and are very inexpensive. Off the shelf at the local garden centre it is 8$ for 110L (3.88 cubic feet) cyprus here is 25$ for 22L (0.8 cubic feet) I actually get coco coir for quite a bit less as I ordered a bunch when one of the local organic farmers did his yearly order and got it for about half that price it is hard to convert as I got weight over volume.