Interestingly enough, carrots last for a really long time in the fridge. I usually toss them out when they get that white, dry coating on them. In addition, there should be a 'best buy' date on the bag; use this as a general guideline, but most of the time, they are good past then. Fresh, whole carrots should last about 4-5 weeks in the fridge. Baby carrots last for about 3-4 weeks. share | improve this answer. answered Jun 13 '14 at 20:42. user25433. 1. add a comment |. up vote -1 down vote. If they are just going soft and not slimy then it is time to make cream of carrot soup.