Unless you have a soil that is low on the micronutrient magnesium, it is nothing more than a feel good exercise. It is just the chemical Magnesium sulphate. If you have acid soil, use dolometic limestone, where one of the ingredients is magnesium carbonate.
Last summer, I just stuck my tomato seedlings in the ground and they did absolutely nothing. I got very few tomatoes from 27 plants. This spring, I dug each hole, sprinkled in a little epsom salts and bone meal, and I got a bumper crop! I would like to believe that the difference was what I put in the soil this time.
I will just add this. Just do a google on "epson salt gardening" pick a few sites and just start reading, and you be the judge. I have yet to use it and I'm still doing homework on the subject, maybe next year.
An old timer recently told me he sprinkles Epsom salt around the base of his tomatoes to help the fruit grow and ripen,.. his claim was the fruit benefits from the sulpher in the product... hard to beat an old timers advice!?!?
I have been using Epsom salts for 2 years now and I am having good results with tomatoes . I have about 30 fruits on one plum tomato plant. I got the info on goggle. My belief is if it is good for humans its good for plants
It helps the plant process chlorophyll, or green up in other words, you would do a world of good to just use sulphur in the area and turn in, tomatoes are heavy feeders, and last year was super weird for veggies, lime in hard ground helps the plants uptake the nutrients they need. You will find that in some areas of the country where water is real hard, a slight addition of vinegar - too much will kill plants- is used and does wonders to help the plants.
Bone meal helps BULBS. When planting bulbs bone meal is used- when you first set them out, if you have dogs you will find them digging where you have applied blood and bone meal and trying to eat the dirt,