One tablespoon to one gallon of water. Feed your plants at least once every two weeks. Works especially well on peppers. Put a tablespoon in the hole then stir it into the ground then plant the pepper You will see a big difference when you do this. It is magnesium and from what I read the entire east coast is deficient in this. I fed a neighbors peppers in Florida this winter and he was really surprised on what he got from three plants.
I started using it last year, and it really made a big difference in the yield I got from my pepper plants. I also put some into a spray bottle and spray my tomatoes and I haven't had any problems with blight.
I've been using it for about 35 years,i take around 10 oz of epsom salt and 10 oz of urea and mix in a large plastic bucket (6 gals)let set for 24 hrs and then you can spray the leafs lightly once a week also make sure your plants are about 6" or higher.I spray all my plants from garlic to potatoes.
I work in a commercial greenhouse and we mix Epsom salt in with all of our fertilize that we use. We water everything we grow with the same fertilizer mix, vegetables and flowers. We started using it last year and all the plants seem heather.