Question
What type of soil do lady slippers need? I am refering to the pink or the yellow. Can they be fertilized for better growth? How can you propigate them? These are on my property

Answer
It is interesting that you have both because they rarely grow together.  The pink ladyslipper requires a very acidic soil whereas the yellow ones are much more adaptable.  Both want woodsy soil (they do, after all, naturally grow in the woods) high in organic matter.  The pink one will tolerate drier sites.

Propagation is by seed only and is best left to Mother Nature and specialists.  For more information see William Cullina's Wildflower Propagation book.  I cannot put my hands on my copy at the moment, but the New England Wildflower Society has information about it on their website.  Cullina is their horticulturist and propagator.

I would not fertilize them.  Their nutritional needs are attended to by mycorrhizae, naturally occurring soil organisms.