Epsom salt does not help plants grow faster, as indicated by research conducted at Delaware Valley College and at Auburn University. Due to the many variables in the soil, the weather and other conditions, research is ongoing according to Garden.org.
Formal research has thus far failed to demonstrate the benefits of Epsom salt claimed by many gardeners who use it to treat peppers, tomatoes and roses. According to users, Epsom salt products healthier, greener leaves, larger, more robust plants, tastier peppers and sweeter tomatoes. Some rose growers claim Epsom salt helps prevent plant diseases and produces bigger, more colorful blooms.