Whether it is hard wood or soft wood, you can dry it all freshly sawed. Having said that it will cost more for time in the kiln since air dried lumber in the kiln will take less time to dry. The soft wood that I put into the kiln had the ends coated with anchor seal, as your probably know, this is a wax paint that keeps the moisture from escaping to fast from the end grain. The wood had also been sitting out for about 1 year. The load came out great with little to no end splitting.
RE: How I built a wood kiln out of a 20' shipping container