Epsom salt contains magnesium and sulfur. These ingredients improve the uptake of nitrogen and phosphorus, increase chlorophyll production and help seeds to germinate, according to the Epsom Salt Council.
Because the salt aids in the absorption of phosphorus and nitrogen, fertilizer can be better utilized by the lawn. Greater chlorophyll production helps grass process more sunlight into food, which means better growth and appearance.
Homeowners should apply 3 lbs. of Epsom salt for every 1,250 square feet of lawn, according to the Epsom Salt Council. The application may be made dry or diluted in water. Cornell University Assistant Professor Neil Mattson recommends mixing Epsom salt with fertilizer for application.