Is Epsom salt good or bad for my garden beds?

What is Epsom salt

Epsom salt, also known as magnesium sulfate, is a chemical compound made up of magnesium, sulfur, and oxygen.  Despite its name, Epsom salt is a completely different compound than table salt.  It was most likely termed “salt” because of its chemical structure.

Henry Wicker discovered Epsom salt in Epsom Common in Surrey, southwest of London.  He was herding his cattle when he accidentally came across a pond.  But despite the arid conditions, his cattle refused to drink the seemingly clean and clear water.  After more research, he discovered that the water was bitter and gave out a white substance (a salt) when evaporated.  This white substance came to be known as Epsom salt.

According to the National Center for Biotechnology, Magnesium (Mg) is an essential nutrient for various fundamental physiological and biochemical processes in plants.  These processes largely involve chlorophyll synthesis, production, transportation, and utilization of photoassimilates, enzyme activation, and protein synthesis.

Sulfate, a mineral form of sulfur found in nature, is an equally important nutrient for plant life.  It is essential to plant health and longevity and aids in the production of chlorophyll.  Sulfate joins with the soil to make key nutrients more effective for plants, including nitrogen, phosphorus, and potassium.  Sulfate works with magnesium to create a blend of minerals, nourishment, and health for your garden.

These are the only two nutrients that Epson salt will give your garden.  If you add constant organic matter to your garden, your garden will hardly ever need magnesium, calcium, or sulfur.  Adding these nutrients to your garden when not required will cause more harm, inhibiting the plant’s ability to take up nutrients.

What does Epsom salt do in the veggie garden?

Some gardeners believe Espon salt is every gardener’s best-kept secret, while others claim Epsom salts are useless and will be detrimental to the condition of the soil.

Common misconceptions about Epson salt

Help with blossom end rot?  (BER)

Epsom salt doesn’t stop or help BER.  BER is caused by a calcium deficiency, usually induced by fluctuations in a plant’s water supply.  Because calcium is not a “mobile” element in plants, even brief changes in the water supply can cause BER.

It is a great fertilizer.

Epsom salt is not a fertilizer or plant food.  It contains some elements that plants need, but not all of them.

If you know your soil is deficient in magnesium, adding Epsom salt to your garden soil can be a good idea.  However, most garden beds will maintain plenty of magnesium, sulfur, and other nutrients if you regularly add organic matter to your soil.  If you suspect your soil has a magnesium deficiency, I suggest testing it before adding Epsom salt.

Improve flower production, especially roses.

There is no evidence that Epsom salts boost the flowering of roses or other shrubs.  The magnesium in Epsom salts can only supplement a slow-release rose fertilizer containing nitrogen, potassium, and phosphorus.

Spraying with Epsom salts can deter pests.

There is no scientific research to support claims that Epsom salt can deter pests and some diseases in trees or other plants.  I tested Epsom salt to prevent pests and had no results.

In conclusion

Epsom salt should not be used consistently in the garden.  It will do more harm.  The magnesium in Epsom salt is highly soluble and can leach or run off into water supplies, contributing to water pollution and escaping the soil it’s meant to improve.

I recommend watering your vegetable beds and grass with Epsom salt at the beginning of the season and then not again.  By adding organic matter weekly to the garden, you should never have a magnesium or calcium deficiency.

Keep adding organic matter to your garden.  My motto is: if it grows, it goes.  Your garden will forever thank you.

So why buy Epson Salt?

It is fantastic for your health.  Read here for more on why you should use Epson Salt.

I prefer to buy my Epsom Salt from Bulk Epsom Salt.