I’ve always used powered Epsom Salts in the bottom of my hole when I transplant my tomatoes in late spring. I read it helps with producing more blossoms and hence more tomatoes. It’s also good for peppers and roses. Epsom salt is a natural mineral that was originally found in a well in Epsom, England. It is magnesium sulfate. Magnesium is critical for seed germination and Sulpher is used for lowering the pH level in alkaline soils like we have here in New Mexico. Sulfur, is also a key element in plant growth.
What I didn’t know was that it is more immediately available to tomatoes and peppers when sprayed on your plant’s leaves vs sprinkling it on the ground. Dilute 1 tablespoon of Epsom salts with one gallon of water, and applied as a foliar spray. When applied this way, Epsom salts can be taken up quickly by plants.
Here is an internet article on Epsom Salts that goes into more detail about it, a trial using it, and how to use it. From now on I will be spraying it on my plants instead of adding to the soil.
I do not add Epsom salts to my other vegetable plants, just my tomatoes and peppers.
Here is the complete article from Garden.org on Epsom Salts.