Epsom Salt for Garden Plants | The Old Farmer's Almanac

Jun 24, 2025

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Some gardeners swear by Epsom salt as a gardening hack. We’re here to tell you that Epsom salt is good for neither plants, such as tomatoes or roses, nor the soil. Yes, it’s one of those gardening myths. Learn more—and let’s talk about alternatives.

Most gardeners love a reliable home remedy and are eager to embrace a magic bullet. This is the case with Epsom salt. It’s supposed to make flowering plants bushier and blossom more and make peppers and tomatoes more productive. But is it really a miracle cure-all? Can Epsom salt be harmful? Let’s separate fact from fiction.

Epsom salt is the chemical magnesium sulfate (MgSO4)—which means both magnesium (about 10%) and sulfur (about 13%).

Bottom line: No, Epsom salt is not beneficial for plants.

Before heading to the drug store for some Epsom salts, look for a slow-release form of magnesium that will have longer-lasting effects, such as magnesium-enriched biochar or kieserite. If your soil is acidic, dolomitic limestone will raise the pH and add magnesium.

Save the Epsom salts to soothe your tired, aching body after a day in the garden!

Read more about gardening myths!

Have you ever used Epsom salt in the garden? What was your experience?

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Bob Martin (not verified)

1 month 2 weeks ago

Some of the pepper plants in my nursery were turning yellow so I diluted some epsom salt in water and sprayed it on the plants. Within 2 days the color had changed to a darker green color and kept that color through to transplant time. I will continue to use it when necessary.

Gill (not verified)

2 months 1 week ago

I used Epsom salts, diluted as recommended for yellowing camellia leaves, & also on magnolias, rhododendrons & roses.I have clay based soil, gets dry. I was pleased to see the camellias etc gradually green up ( acid plant feed hasn't helped) & my pink magnolia Stellata has produced the deepest pink ever this Spring.It was very pale pink before. I think it's worth stressing that E salts needs to be properly diluted as advised by pro gardeners (in UK), & not used as dry powder.

Joshua Coyle (not verified)

4 months 1 week ago

Never heard of anyone treating blossom end rot with Epsom salt. It's true over doing magnesium will lock out calcium as well as potassium, but same can be said with calcium locking out potassium, magnesium, phosphorus, manganese, and iron , and too heavy with potassium locks out magnesium, calcium, and zinc. The competent gardener will have read the application rates on the packaging for the given crop. He or She would have more than likely browsed the gardening section (If savvy enough may even googled a few key descriptive words) and at some point saw the calcium nitrate. Even with a vague description "Cures blossom end rot in tomatoes!" Id bet most cultivators worth their epsom "salt" could string the key words together and draw a connection to their gardening woes.

Linda L Lillie (not verified)

1 year ago

Thank you so much Robin for writing this article. As a horticulturist (retired) I have been telling people for years to stop using Epsom Salts! And we still see so many write ups suggesting its use. Your article will reach many people and hopefully change their minds about using it. It's not good for the plants and it's harmful to our previous water supply! Thanks again!

Charles (not verified)

1 year 7 months ago

Why do you say Epsom Salt is a myth and recommend against it,

Then go on to recommend an OMRI certified magnesium/Sulfate which is the same thing in composition?

Sally (not verified)

1 year 1 month ago

In reply to Why do you say Epsom Salt is… by Charles (not verified)

I've been using Epsom salt for years and it's been very beneficial why do you say it's not

DEL (not verified)

1 month 2 weeks ago

In reply to I've been using Epsom salt… by Sally (not verified)

We have been using a 2/1/1 combination of sugar/bone meal/epsom salt for many years as a substitute for regular fertiizer when planting ALL vegetables and having super results. This combination was suggested to us many years ago by a 'Master Gardener'!

The Editors

1 year 7 months ago

In reply to Why do you say Epsom Salt is… by Charles (not verified)

Thank you for bringing this to our attention. We have revised the text.

Tommie miller (not verified)

2 years 1 month ago

In my north Alabama raised bed garden I use epsom salt on almost all of my vegetable plants. They are greener and healthier and have good production. On my tomatoes plants I also put a bit of dry milk powder in the planting hole which gives them calcium. This year I am trying to grow squash as a climbing vine to save room and try to miss the vine borer, I also sprinkle cinnamon powder around my plants to ward off fungus and cayenne pepper to ward off animals..

Jennifer Keating

2 years 1 month ago

In reply to In my north Alabama raised… by Tommie miller (not verified)

That’s wonderful that you are having success using epsom salts in your garden. Thanks for sharing!

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