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Epsom Salt for Plants and People

Epsom Salt for People

Epsom is most commonly thought of as a healing remedy for soaking tired feet or a hot restorative bath, but it can also be a wonderful supplement in your garden. Epsom salts do far more than relieve tired and aching feet or provide beneficial cleansing and detox.

Life style hacker, self-experimenter and author of the acclaimed 4 Hour Workweek, The Four Hour Body and The Four Hour Chef—books with loads of survival-hacking how-to’s—enjoys daily Epsom salt baths for therapeutic benefit. Author, Tim Ferriss says, “I take hot baths every night when at home. Nearly always, I add epsom salt (typically 4-8 cups), which facilitates muscular relaxation and recovery. Rather than buy small boxes at CVS or Safeway, I buy [Epsoak] in bulk and store it in rolling dog-food containers. This is a good use of Amazon Prime.” So…

What is Epsom Salt?

Epsom salt is actually mineral deposits found in the water in Epsom, England. The chemical composition is hydrated magnesium sulfate. Like people, plants need magnesium. Magnesium helps plants use nitrogen, sulfur and phosphorus.

Epsom salts aren’t salt!

Plants need magnesium and sulfate, so yes, Epsom salt or magnesium is good for plants, and Epsom is one way to give it to them.



Epsom Salt for Plants

Epsom Salt is a Magnesium Sulfate Fertilizer

Plants use sulfur to produce amino acids and vitamins. Sulfur is also the compound that gives many vegetables, including broccoli and onions, their distinctive flavor. Most garden soils have sufficient levels of sulfur, but magnesium deficiencies are common, especially in old, acidic soils and the highly alkaline soils found in the western states. So Epsom salt is basically a magnesium sulfate fertilizer.

Severe magnesium deficiencies can cause stunted growth and yellowing of the leaves between the veins. However, the only symptom you might see is slow growth and fewer blossoms or fruit.

Yellowing leaves and slow growth might indicate a magnesium deficiency.

Soil tests can detect severe magnesium deficiencies. In some cases, though, a soil test might reveal that your soil has adequate magnesium, yet plants are unable to access it due to high levels of potassium and calcium.

Which Plants Need Epsom Salt for Magnesium?

Tests conducted by the National Gardening Association revealed that Epsom salt made the biggest difference for the growth of these plants:

  • Tomatoes
  • Peppers
  • Roses

The best way for the plants to absorb the magnesium sulfate nutrients if through foliar application, by spraying the epsom on the plant leaves. It’s interesting to note that this is similar for humans. E.g., external application to the skin is the best way for us to absorb magnesium, and leaves are like the skin of the plant.

Where Epsom was applied, the tomato, pepper and rose plants were healthier in foliage flower and fruits than the test plants that did not receive the Epsom magnesium sulfate.

Epsom salt made the most difference on tomatoes, peppers and roses.

So how much Epsom to apply?

Epsom Salt in the Garden

If you’ve tested your soil and determined it needs more magnesium, here’s how to make and apply Epsom salt fertilizer.

  • ½ cup granules sprinkled around the base of roses in spring
  • 1 Tablespoon Epsom to 1 gallon water – spray roses after leaves emerge and again while flowering
  • ½ cup in the fall before the leaves drop


Epsom Salt for Tomatoes

To treat tomatoes and peppers, dilute 1 tablespoon Epsom salts with 1 gallon of water. Spray the plants after transplanting, when they first flower and when they begin producing fruit. In addition to producing more abundant fruits, Epsom salts can also reduce problems with blossom-end rot, which are believed to be caused partially by a magnesium deficiency.


If you’re not sure if you have a magnesium deficiency, skip the soil applications and stick to foliar applications instead.

Source: 1)

When to Test Soil

The best time to test your soil is in spring before planting. However, if you’ve already gotten started, you can still test it. In fact, if any plants are ailing and you’ve ruled out pests, amending and treating the soil, may help. Often, your county extension service will test your soil for free. Call them to see.

Or you can get soil test kits. This one tests for magnesium. To test your soil for pH, Nitrogen (N), Phosphorous (P) and Potash (K) levels the Rapitest Soil Test Kit is the best seller on Amazon.

It’s far better to test your soil early and amend as needed than to lament over poor crop yield. Prevention is always best.

You may also enjoy these articles on soil testing methods and on tomatoes.2)

Epsom Salt for Plants and People

So yes! Epsom salt is beneficial for your garden… and for you! Next time you come in tired and sore from working out in the garden, be as kind to yourself as you are to your plants and enjoy an Epsom salt bath! Oh… and remember to share it with your tomatoes, peppers and roses!

You might even save some of your epsom bath water and share it with your plants as prescribed. You and your plants will both feel better and be healthier!

After a day of gardening, treat yourself to an Epsom bath!

For gardening, you may prefer a 50 pound bulk size Epsom Salt which you can get from your local home store, or from Amazon, and delivered to your door for free is you have Amazon Prime: Try Amazon Prime 30-Day Free Trial

For a long list of benefits of Epsom salt for people… and why you’ll be wanting that soak, you may enjoy this article.

Happy Growing!

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