To add magnesium to soil, I heard you can use 1 cup plain Epsom salt to a gallon (or 2?) of water. I tried this 2 yrs ago & the tomatoes planted in this raised bed did well. And, my strawberries jumped (or birds helped?) from nearby ground to raised bed & did exceptional. Your thoughts/advice on using Epsom salt this way? I don't want to add "salt" to our soil!