Epsom salt contains magnesium and sulfur, two essential nutrients that plants require for healthy growth. But...
According to Old Farmer's Almanac, however, Epsom salt is not good for plants or the soil. This trending garden hack is a "gardening myth".
If you soil is sandy, lightweight, and/or low pH (conditions that are prone to magnesium deficiency), then add compost to raise the level of organic matter in the soil.
Sulfur helps plants with vitamins and plant proteins. If a plant has young leaves that are yellow, a lack of sulfur may be the culprit. Note that sulfur is not commonly deficient in garden soils in North America. If you think your plants lack sulfur, a sterilized manure is a good additive to the soil. Our Resources page has an excellent resource for sterilized manure - and it's free!
Read the Old Farmer's full article about Epsom salts here.