Well, the info I have on Epsom is:
Houseplants: 2 tablespoons per gallon of water; feed
plants monthly. Tomatoes: 1 tablespoon per foot of
plant height per
plant; apply every two weeks.
roses: 1 tablespoon per foot of
plant height per
plant; apply every two weeks. Also scratch 1/2 cup into soil at base to encourage flowering canes and healthy new basal cane growth. Soak unplanted bushes in 1/2 cup of Epsom Salt per gallon of water to help roots recover. Add a tablespoon of Epsom Salt to each hole at planting time. Spray with Epsom Salt solution weekly to discourage pests. Shrubs (evergreens, azaleas, rhododendron): 1 tablespoon per 9 square feet. Apply over root
zone every 2-4 weeks. Lawns: Apply 3 pounds for every 1,250 square feet with a spreader, or dilute in water and apply with a sprayer.
trees: Apply 2 tablespoons per 9 square feet. Apply over the root
zone 3 times annually. Garden Startup: Sprinkle 1 cup per 100 square feet. Mix into soil before planting. Sage: Do not apply! This herb is one of the few
plants that doesn't like Epsom Salt. **This came from the Epsom Website**