Just to clarify a bit....peat MOSS, and "peat", are two different things....sort of
! Peat moss....comes in a 'bale", like straw, or hay, and , when it's shredded, is used in a lot of 'soilless ' potting mixes. "Peat", on the other hand....is what the "peat moss", and other "swamp" plants turn into after a few thousand years of aging.....it is actually "soil". Just wanted to throw that out there, because if you buy a bag of 'peat".....that's probably NOT what Schreiner's uses!
Sphagnum Moss is the 'right" name for "peat moss", and you should be able to find it, either shredded, or baled, at a good garden store.