How long does it take garlic to germinate in the fridge? If left in the fridge, how long does garlic take to germinate? I have experienced the green sprouts in the past, and was able to chop them off and eat the remaining garlic. I am curious add to how long that takes as I cannot remember.

This way I will know how much garlic to keep in the fridge at my friend's house, based on how much is used per week, since my friend insists that it must be kept in the fridge.

If I plant the garlic that has germinated in a pot, will it grow? How do you grow it?
Germination of garlic is a gradual, slow process, and how long it takes depends a lot on how close to sprouting the garlic was when you originally bought it. Seems to me it would have to sprout faster at room temp, than refrigerated, anyway.

I routinely keep garlic in the fridge (shame on me!), and sometimes the garlic will keep in the fridge for at least a month without sprouting (That's about how fast I use it, so I don't have data past a month). On the other hand, I have seen nubby little green/purplish sprouts (abt. 3mm long?) on garlic which I had just purchased; cut them off; garlic was fine - just like your experience. 

I guess the reason you want to keep the garlic in the fridge during your stay at your friend's house is to avoid unnecessary rancourous arguments - yes? So here's the thing: your friend may be wrong, but for the layman, it's not a huge deal to keep the garlic in or out of refrigerator, as he likes.