Can I Use Epsom Salts to Fertilize My Garden, Fruit Trees and Houseplants?

http://www.motherearthnews.com/organic-gardening/epsom-salt-fertilizer.aspx

Can I use Epsom salts to fertilize my garden, fruit trees and houseplants?

You should never use Epsom salts (magnesium sulfate), lime or other single-ingredient soil amendments unless you have had your soil tested, and the results confirmed that you need to add that particular ingredient. Adding Epsom salts would benefit some soils, but it could be harmful in others. The only way to know which situation you have is to get a soil test.

— Cheryl Long, editor in chief