Original Source:http://banjobasics.julieferris.com/more.html

Strings

They don't require a lot of work but there are a few things you need to know to properly maintain your banjo. Number one at all times is, keep it clean. Dirt and smudges are your biggest enemies. Before you pick up that instrument, make sure you haven't just greased the tractor and forgot to wash your hands. Of course no matter how well you wash your hands, a small amount of oil will be put on the banjo and also the strings from your fingers. The greater cause for concern is on your strings. They don't vibrate like they need to when they become soiled. I use that word soiled and its not like youre going to have clods of dirt on the strings, but you can easily end up with small clumps. Im sure you can look at what the string manufacturers recommend on length of time to replace your strings, and its fairly often. (Ok heres one of those my opinion things again) I prefer to change my strings about every 20 playing hours. Actually I have noticed that after about 20 to 30 hours the strings will sound a bit muted when capoed, that's when I know its time to change them. Not everyone has the same idea, though as I know some pickers that change theirs about every 8 hours. Others even change theirs more often, every 2 or 3 hours. Yet others wont change them unless they break or rust through. One thing that is nice about Banjo strings is that they are relatively cheap, from 3.50 a set up to about 5.50 here in the midwest. Of all the instruments I play, they are the cheapest. I also picked up a little trick from an old guitar player, about extending string life. When you finish playing, get yourself a soft cloth such as a baby diaper, and wipe down the whole banjo, especially the strings. This helps to remove the oils you just placed on it, before the dust and dirt can accumulate. Simple as this sounds it really works great and helps to keep your banjo and strings in better condition. One other thing that will add life to your banjo and strings is to keep it in a good case when not in use. If dust and dirt cant get to it its better. I know a lot of pickers like to show off their banjos, some even hang them on the wall but its better for them to be in a good case.