The “Epsom Salt is Good for the Garden” Myth-Debunked!


epsom salt gardenThe “epsom salt is good for the garden” myth busted, once and for all. That is the topic of today’s post. What is epsom salt exactly? And where did the plant benefit story come out of? So many garden-related “old wives tales” and so little time, so let’s get into it now.

One day, I don’t know when but it was back in the 2010s, I think, I was out at Ace Hardware getting a jump on my spring planting essentials and picking out some plants while they were at their peak of newness for the season (right around the second week of March, usually, down here) I always get them first and nurture them indoors until the last frost is over when I start to transplant them.. I ran into another shopper and we must have gotten to comparing notes about plants and she said “You know, epsom salt is really good for a plant fertilizer “

Have I tried that? Admittedly, yes. Did I get any results from it to speak of, in terms of more growth, deeper green foliage or fruit output? Also, admittedly, no.

I don’t think I ever relied on it as a fertilizer per se, maybe as a booster, and even then, only a supplemental product. Any results I have gotten from it were minimal at best. SO why does everyone say that epsom salt has all these benefits for plants. Does it really work for them or is it all a matter of the placebo (sugar pill) effect?

What is epsom salt, actually?

You will find epsom salt at most place that home health remedies can be found, in anything medical related and drugstores. That’s your first clue right there, it is not found at the plant nursery, Lol. It’s a crystalline form and dissolves in hot water, It makes a good laxative and as a form of bath salts, helps muscle sprains and relaxation-e.g will dissolve in bath water to soak in to relax and soak in after a long busy day. The chemical component of epsom salt is magnesium sulfate. So magnesium and sulfur. Both of these are 2 essential nutrients for plants,

This particular brand we got, has got rosemary and mint oil added to it….

epsom salt good for plants
Magnesium sulfate-the main component

If you have any plants that are deficient in either of these nutrients, It could be a helpful move, but you should do a test on your soil first. Most fertilizers and soils naturally carry a normal amount of magnesium and sulfur already without us needing to supplement it with any extra…and if that’s the case epsom salt may even be harmful, as you’re ratio will be out of balance. Most fertilizers will have this present. But a soil test is where the rubber hits the road so get it tested first before you add anything.

But if there is a real deficiency of magnesium or sulfur, and you insist on trying it out, be sure to dissolve it first in hot water and let it cool and also be sure to dilute it with more clean water.

What about epsom salt for garden pest control?

Also you may have heard some people say that epsom salt can be a repellent for some garden pests, including slugs or snails. Again, more bunk. If you’re sprinkling salt around your plants to act as a deterrent, stop it. They’ll climb right over it. Every experienced gardener worth their salt (no pun intended) can tell you that the key to beating the slug problem is a bait/trap with something fermented inside to lure them. Epsom salt doesn’t come anywhere close to that, whether dissolved or not.

A few Exceptions….It May Benefit Tomato Plants

Tomato plants are one crop type that could benefit from the addition of epsom salt – IF you have a problem with the issue of  yellowing leaves. which is usually brought a out by a magnesium deficiency. One thing that can bring this about is overwatering, so watch out for that -of course heavy rain could be responsible too. 

If you notice leaves turning yellow it is caused by the sugar uptake outpacing what is produced through photosynthesis. Magnesium has a strong role to play in the production of sugar. Contrary to popular belief, epsom salt does not produce sweeter tomatoes – that may be an urban legend, as the sweetness of tomatoes may differ among different varieties.

epsom salt tomato plants

But it will not correct blossom-end rot, which as I may have stated earlier, is caused by a calcium imbalance. Just want to make that part clear.

You can use dissolved epsom salt as a side dressing or addition to the soil, it can help balance out the alkalinity levels brought about by too much moisture. I would make it part of a routine to add every three weeks or so until symptoms improve.


So I hope to have enlightened you a little about the (mostly) hype around epsom salt – and second only to the notion of coffee grounds having this kind of value. I don’t know if it’s folklore or anecdotal, but the best way to conclude this, big takeaway: test your soil and get some real soil additives. Proceed to it IF  you can confirm a real deficiency in magnesium. In the meantime, Save your epsom salts to soak in a tub after a long hard day of gardening instead.

2 thoughts on “The “Epsom Salt is Good for the Garden” Myth-Debunked!”

  1. Coffee grounds and tea grounds have done my plants wonders! Both have been used not only grounds, but also liquid coffee and tea; both, every other watering. Blooms are larger and deeply colored. I can attest that both have worked marvelously for me and would recommend both to anyone. Thank you.

  2. I’m glad to hear they have worked out for you, I know there’s always exceptions…May I ask what you’re currently growing specifically? I’m a little curious.

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