[Steve Graffham]

I know that I am replying to an historical post but it seems to be the most relevant one.
After years of hibernating my adult trio of Hermanns in a drinks chiller, I decided last year to offer the opportunity for them to dig down and hibernate naturally in a greenhouse. Two of of the tortoises dug down in the greenhouse soil on 10th and 19th October 2020 respectively and the remaining female who always slows down a lot later just wouldn't dig down and had to be placed in the drinks chiller.
Using the drinks chiller, I usually restrict the hibernation to 16 weeks. However now two of my tortoises have dug themselves down naturally, I am wondering if it will be best to leave them to emerge when the the weather warms up or to dig them up and start using the greenhouse heating.
The greenhouse remains mainly unheated through the winter and only heated if the temperature drops below freezing or during long spells of very low temperatures.
One of the females is only about 3 inches below the surface of the soil and the smaller male is a bit deeper.

Past experience has shown that in some years after bringing the tortoises out of the fridge into the heated enclosure, they will try and dig down to continue hibernating.
I am keen to learn of other tortoises keepers (especially Sandy's) experience of natural hibernation and the duration.

Many thanks

Steve Graffham