I take it that you mean shreaded peat moss. Peat moss is a soil amendment and retains a lot of water. Using straight peat moss as a soil substitute would probably keep your roots too moist - causing problems. Also - peat moss tends to be a little acidic, so straight peat moss would surely cause ph problems. Peat moss should be blended with other stuff to make a potting mix, that way you can balance out the strengths and weaknesses of each ingredient.
