Clint Waltz, extension turfgrass specialist, spoke with Country Living about the popular myth that Epsom salt is a great “natural” soil amendment for your garden.
Gardeners have claimed that Epsom salt is beneficial to plants like tomatoes, peppers and roses. For generations, Epsom salt has been credited with everything from increasing harvest to keeping slugs away.
However, many researchers have stated that these claims are not based on research.
Many gardeners use Epsom salt when they believe their garden is lacking in sufficient magnesium. Historically, gardeners would apply magnesium sulfate, a chemical found in Epsom salt, to soil and leaves to turn leaves from yellow, red or purple to green. Unfortunately, gardeners may simply be attempting to solve a problem that isn’t there.
“Lawns will rarely be low in micronutrients such as magnesium. This is a non-issue for most homeowners,” Waltz said. “You’d need a soil test anyhow to know if you’re missing a specific nutrient before you start putting anything down.”
Without knowing what’s already in the garden soil, gardeners could be doing more harm than good if they apply Epsom salts. The overuse of magnesium sulfate can cause salt injury to plants and lead to deficiencies of other essential plant nutrients like iron, boron and potassium.