Here is an excerpt from the Epsom Salt Council.
Why Epsom Salt Works
Magnesium and sulfur are two naturally occurring minerals that are major components of Epsom salt. Magnesium is a critical mineral for seed germination. Plants use it to produce chlorophyll and as an aid in the absorption of phosphorus and nitrogen. Sulfur is also a key element in plant growth, helping produce vitamins. Tests by the National Gardening Association show that Epsom salt helps produce more flowers and makes pepper plants grow larger.
Epsom Salt was found in a well in Epsom England a very long time ago and has been used on gardens and people as well. It is a natural, organic substance that I use every spring on my entire garden.
