Somehow or another my snakes thrive. They also seem to do fine in basements , porches and even summer back vivariums in zone 7 or above and of course they do fine inside all year around. If your snakes are the indoor type get a hot rock. Garters are excellent eaters and will take a variety of foods. If you can't get a garter to eat there is something way wrong.
Variety seems to be the key to their domestic care.
Simply rub the small rodent with a bit of fish or worms and watch the Garter magic happen. In no time they will be feeding like a kingsnake. Imagine taching a Kingsnake to eat fish. It would never happen. Basically , if you seriously keep garters you will need to visit your local bait shop on occassion, your pet shop a bit more and your back yard or local pond even more.