Shortly before Henrik was born I stopped feeding the turtles any fruits or veggies. While they had access to wild food in the form of bugs and plants by withholding anything else, coupled with a few warm water soaks prior to hibernation, would allow their gut to remain relatively empty for their long winter's nap. Had I not done this any food that they had left in their gut could rot, making them sick. I then got 3 clear rubbermaid containers, drilled holes in the top and filled them with moist but not wet peat moss and some straw. I placed the turtles in them, one in each, then simply placed them in the fridge. Have to make sure that the fridge temp remains between 35-45 degrees F and does not freeze. This is the necessary temp to hibernate them at. I must admit that it goes against one's nature to place a living animal in a fridge and it does take some getting used to. You must then wake them up every 4-6 weeks by putting them in a room temp setting. Simply check them out for health and start the process over minus the soaks. Basically just put them back in the fridge. The fridge must be opened periodically to get oxygen available to them otherwise you have to run an aquarium air pump and tube into the fridge to supply air. Cold blooded animals are quite amazing creatures.
Here is a photo of the containers in the fridge. Once the temp hits freezing I will move the containers to the barn where the heat that the horses produce keep the barn at about 40 degrees F all winter long, even at its coldest point. The reason I can't keep them in the garage fridge all winter is that the ambient temp in th garage will affect the fridge temp dropping it too low.