Going to cutnpaste from another answer I just posted:

If you are east of the Mississippi find an agway. Get yourself a few bags of manure humus. Get a bag of perlite also at agway. Mix 2 parts to 1 part of the humus to perlite. Re-pot in this mix. Problem solved. If no agway you can get manure humus at home depot but I do not vouch for it's quality. This is a cheap and good quality soil for growing.