Posted: 22/06/2014 at 09:40
When you say "mud" that sounds like it's a bit wet, so just check it doesn't smell sour, in which case it wouldn't be good to add.
Some things aren't always rotted down completely, such as tree/bush cuttings, hard veg stuff, such as sweet corn husks. Personally I would sieve these out if I was using it in a pot/planter, and put them back in the compost. If your planter is fairly large then it should be ok, and mix it in esp. if it is a bit wet.