I bought ginger root months ago, and I didn't use all of it. I've kept it in the fridge and it still seems good. How long will it last?
Eat By Date claims a shelf life of about one month, in the refrigerator, which matches my experience.
Ginger root is a living rhizome, and is the plant's way of storing energy to grow later. As long as it is firm, not slimy, with no signs of a mold, with a good aroma, you should be able to use it.