The article linked below by Gardening Know-How is timely. In our locale our flowers are getting ready to bloom and Epsom salts improves flower blooming and enhances a plant's green color.
The article advises getting your soil tested first to determine if it is deficient of magnesium, which Epsom salts can add. Click here for information on how to get a soil test.
"Many plants, like beans and leafy vegetables, will happily grow and produce in soils with low levels of magnesium. Plants like roses, tomatoes, and peppers, on the other hand require lots of magnesium, and therefore, are more commonly watered with Epsom salt."
Why put Epsom salts on your plants, things to watch out for (i.e. overdoing), and how to water plants with Epsom salts in the article here.