No, Epsom salt necessary plants is a claim that falls apart for most home gardens. Your garden soil that gets compost or fertilizer already has enough magnesium. Most of you who apply it are spending money on something your soil does not need at all.
So do plants need epsom salt ever? Your plants do need magnesium because it forms the core of every chlorophyll molecule. Without it, your leaves turn yellow and growth slows. But most garden soils already have plenty. I tested my own beds after three years of monthly treatments. The lab showed my magnesium was well above the good range. All those treatments had done nothing but push a nutrient that was already high even higher in my soil.
The epsom salt gardening myth that it cures everything from yellow leaves to poor fruit has spread across the web for years. Blog posts and social media tell you to use it for almost every problem. None of them mention soil testing first. Alabama Extension says that adding more above what your soil test shows will not make your plants grow better. You cannot boost growth by adding more of what is already there.
NC State Extension says something worth hearing. Fixing a low magnesium level is much easier than fixing a high one. Once you over-apply, the extra magnesium fights with calcium and potassium at your roots. Your plants may look like they lack those other nutrients even though your soil has plenty of them. Fixing this takes months of careful work and more soil tests to track your progress along the way.
A small number of gardens do benefit from Epsom salt. They tend to have sandy soil that loses nutrients fast or acidic soil below pH 6.0. Gardens in rainy areas also lose magnesium through natural leaching. If your garden fits one of these cases, get a soil test done. When the results confirm low magnesium, Epsom salt makes sense as a targeted fix.
Spend the $15-$20 you would put toward a bag of Epsom salt on a soil test instead. The test tells you what your garden lacks and what it already has. You will make better choices, waste less money, and avoid creating nutrient problems that take a full season to fix. That one test gives you more value than a whole year of guessing about what your plants need.
I wish someone had told me this before I spent three years pouring Epsom salt on beds that did not need it. My garden looked fine the whole time, not because of the treatments, but in spite of them. Your plants are tougher than you think. They do not need a magic supplement to grow well. They need the right nutrients in the right amounts, and only a lab test can tell you what those amounts are for your specific patch of ground.
Read the full article: Epsom Salt for Plants
