Box turtle hybernation

Question
I have a box turtle in an outside enclosure.  How do I make sure that the enclosure is fit for it to hybernate in?  What materials would be best for me to place in the enclosure to help it be prepared when it is ready?

Answer
Sorry your question waited so long. I hope you got an answer in the meantime. I just joined here as an expert, but box turtles is one of my areas of expertise.

As to your question; it really depends largely on where exactly you are, and what subspecies of box turtle you have. Some subspecies are less tolerant of cold than others. Generally, if you live in a latitude that your subspecies of box turtle does not inhabit in the wild, or you get hard ground freezes, then you probably should not hibernate it outdoors. You really should reside in a southern state to hibernate a box turtle outside. Some people prefer to hibernate their turtles outdoors. I prefer indoors where I can monitor them for illness, hydration status, etc., and maintain more consistent temps. If I can't find a room in the house cold enough, then I'll use the garage.

For outdoor enclosures I recommend several inches of substrate for them to burrow in. I start with a layer of organic top soil or dirt, followed by a few inches of organic mulch, humus, and/or sphagnum moss. If they can get down several inches below where the freeze layer occurs, then they should be ok. But again, it's a risk I prefer not to take, since hibernation is a state of minimal life support for the turtle, and some may not wake up if conditions are not right.

Whether you hibernate indoors or out, it is vital that you determine with accuracy that the turtle is healthy ( with no injuries, illness, or parasites ), is well hydrated, and has plenty of reserve fat stores to see it though it's slumber.

http://anapsid.org/mainchelonians.html
http://boxturtlesite.info