Painting Masonry paint onto Natural Stone

Hi, will be painting our outside garden wall one day at the front of the house and some of the pillars have some remains of natural stone, I want to paint the whole lenth of the wall with some magnolia exterior masonry paint but I read somewhere that you cannot paint natural stone that the paint wont adhere to it, is that true? - most of the natural stone on the pillars is on there sound so I dont really want to chip them off and render it, so is there a way i can paint over it using maybe undercoat, primer or PVA mix or something like that do you think? heres a picture of one of the pillars: