Is there any real benefit to using Epsom salts?
Ask Ken ...
Q. What is the benefit of using Epsom salts on plants? Over the years, I’ve seen it recommended in quite a number of gardening articles. — M. Smith, Suffolk
A. The white powder has many reported health benefits and equally numerous household, beauty and gardenrelated uses.
And it is readily available. If it is not already in your home, you can easily find it in the grocery aisle, pharmacy or neighborhood garden center. The mineral compound MgSO4, a combination of magnesium, sulfur and oxygen, takes its name from the source of its origin — the mineral springs of Epsom, in Sussex, England.
I’m not surprised you’ve seen it recommended in several publications. But despite the many folksy claims of gardeners for generations, the touted benefits are somewhat scientifically inconclusive. What can be confirmed is that Epsom salts have been successfully used to treat intensively grown field crops that were showing symptoms of magnesium deficiency (a hard diagnosis for the homeowner).
Said deficiency in plants would occur for one of two reasons — the soil is deficient or there are nutrient imbalances in the soil or plant. Deficiencies can occur in intensively grown crops on light, sandy type soils, under high rainfall or irrigation, or soils in low in pH. Also, high levels of phosphorous (P) and/or calcium (Ca) can inhibit Mg uptake. Note that Epsom salts is highly water soluble and subject to leaching — not good for the environment.
It is important to note that magnesium (Mg) and sulfur (S) are essential secondary macronutrients. While Mg has several important roles in plants, arguably the most important is that it is the “central role” element in the chlorophyll molecule, and is thus responsible for the color green we associate with plant leaves. Sulfur plays roles in enzyme activation and is a constituent of some amino acids. Plants do need Mg for their metabolism. But, unless you have reason to believe that your plant is actually deficient in magnesium, there are few, if any studies, that show that supplemental Mg will significantly improve plant growth and crop yield. If your soil was limed with dolomitic lime (CaMg (CO3)2), then you’ve perhaps unwittingly added magnesium. And regarding sulfur, it is rarely deficient in soils.
In the past, I have used Epsom salts in the greenhouse with a couple of crops, such as poinsettia. But this was only after a media test indicated a Mg deficiency, and recommended that corrective measures be taken.
With Epsom salts handy, and within easy reach in most homes, it is tempting to “over-medicate.” If you suspect Mg deficiency, tissue and soil samples are recommended before treatment. Foliar sprays and drenches can then be used to treat the symptoms as needed. FYI, the recommended rate is 1-2 tablespoons per gallon spray or drench.
If applying Epsom salts makes YOU feel better, then go right ahead. A little may not help, but it shouldn’t hurt much either. But be sure to save some for your after-gardening soak.
And one more thing (or two) ...
Do you love the mild/ sweet Vidalia onion? They are a favorite of mine. Georgia folk love it so much that for the past 42 years, they’ve celebrated it at the Vidalia Onion Festival, which most recently was held April 25-28. The fest features the Miss Vidalia Onion Pageant and the
Miss and Jr. Miss equivalents, the Vidalia Onion 10K Run, Vidalia Onion Culinary Extravaganza, an onion eating contest, a recipe contest, the Vidalia Onion Carnival, the Onion City Softball Tournament and assorted arts/crafts, music and fireworks. Don’t fret if you could’t make it. The famous Georgia state vegetable began showing up on local grocery shelves just recently.
Email your questions/ address and receive a complimentary package of seeds if your question is chosen for publication. Send questions to wkspen@gmail.com or to Home + Living c/o The Virginian-Pilot, 150 W. Brambleton Ave., Norfolk, VA 23510.