Stage two, part two. After Jim distributed the vermiculite layer evenly, he added the peat moss. It was also dry and dusty, so he kept the mask on. I had purchased 4 2.2-cubic-foot bales since they were light enough to carry and easy to fit in the trunk of our car. Peat moss is a lot heavier than vermiculite which weighs almost nothing, but still, the wind could carry it off. After Jim spread the four bales over the garden, he then watered to keep it in place.
Peat moss, like vermiculite, is a one-time additive to lighten the soil texture, improve drainage and aid in retaining water. It is completely natural.