You may have heard of Epsom salts being used on plants in the garden. Yes, the stuff you see at the drugstore. Those bath salts designed to relieve pain have a place in the garden, too. You wouldn’t think salt would find its way into the garden, would you?
Epsom salts contain trace minerals magnesium and sulfur, which plants need to survive and thrive. Since plants need these minerals to live, using Epsom salts is a way to help your garden flourish. More is always better. Is it really as miraculous as people claim?
In this article, we’ll examine what magnesium sulfate has to offer and why you shouldn’t rely on it to solve your plants’ problems.
Claims About Epsom Salts for Plants
Epsom salt, also known as magnesium sulfate, is a different animal altogether when it comes to the plant world. While table salt might be bad for your plants, Epsom salt is renowned in the gardening community as a plant-friendly mineral.
There are many benefits to Epsom salts for plants. You can find them easily at the pharmacy, they’re inexpensive, and you can apply them easily.
The Internet is flooded with content that touts Epsom salts as a wonder product that can fix everything from garden soil to illnesses.
Runners are well aware of the claim that Epsom salt baths ease aches and pains, but soaking in any hot water does wonders for the body after a hard workout.
Despite loving Epsom salt soaks, I’m skeptical that they’re any different from enjoying a soak with colorful bath bombs.
Likewise, magnesium sulfate has gained a stellar reputation through word of mouth, as has Epsom salts in the garden.
Although I have gotten some great growing tips from grapevine, not every piece of advice is gold. Do not believe miracle claims.
What do people say about Epsom salts? Here are just a few things they say this amendment can do:
- Deter pesky pests from insects to small mammals
- Act as a nutrient supplement
- Produce lush plant life
- Increase flowering rate
- Decrease instances of disease
- Increase germination rates
The idea of something that can tackle just about any problem in the garden is appealing to gardeners. There’s something I can use in every corner, and it poses no harm, right? There’s a problem. Scientific evidence on Epsom salts in the garden is sketchy at best.
Even though magnesium sulfate is highly soluble, it’s entirely possible that it will end up as a contaminant. Furthermore, although it may be an attractive option for gardeners on a budget, it doesn’t provide the value it claims to offer.
Why It’s Not a Gardener’s Miracle Tool
In the same way that humans eat, plants also need nutrients to grow and flourish. However, plants do not require large amounts of magnesium or sulfur. Though they are necessary for growth, it’s unlikely that your vegetable patch or entryway rose bush are deficient in either nutrient.
Also, getting your soil tested is the only way to determine whether your plants are deficient in a specific nutrient or trace mineral. Adding magnesium sulfate blindly isn’t recommended. Furthermore, mulch or compost usually provide the Mg and Su plants require to thrive.
Similarly, the claims surrounding pest reduction and disease eradication are overstated and not supported by scientific evidence.
Epsom salts might seem like an intriguing quick fix, but little evidence supports their ability to prevent infestations. Small mammals are unlikely to be deterred by Epsom salts, which is why you shouldn’t expect rabbits to stop munching on your carrots.
If Epsom salt is added in small amounts, it may not contribute much to your soil’s nutrient composition, but excessive amounts will readily leach out of the ground and contaminate nearby water supplies. Epsom salts, too, become a pollutant when diluted with water and sprayed on plant leaves, which may cause leaf burn. This leaves your plants vulnerable to disease and may even attract pests to your garden.
By the way, Epsom salts for plants do not appear to improve germination. That is because seeds need the right conditions to sprout, not a lot of magnesium sulfate. If by chance some seeds germinate faster, it is not because of Epsom salt.
Many of the claims concerning Epsom salts are misleading since they assume it will improve flowering rates, growth rate, etc. Probably because the seeds are fresh, receive plenty of full-spectrum light, are grown in the proper temperature conditions, and receive adequate moisture.
Can it help with nutrient deficiencies?
However, in the event that your plants are indeed deficient, restoring their health will certainly lead to growth, but Epsom salts may not be the ideal way to get an additional boost.
If your car does not have gas, it cannot run. Fill up the tank, and off you go. Adding too much gas, however, doesn’t provide any additional benefit and may cause problems.
If your plants do not lack magnesium or sulfur, adding Epsom salts probably won’t have a noticeable effect on the growth rate, and may actually harm them. It seems an inefficient use of resources. It doesn’t appear to increase growth or produce more flowers.
A difference between one year and the next or a change between plants might be attributed to environmental factors or actions you’ve taken in the garden. It’s highly unlikely that the magnesium sulfate you added was to blame.
The use of Epsom salts with tomatoes and peppers is also recommended because it protects against diseases such as blossom end rot.
However, adding magnesium when there is no true deficiency may cause blossom end rot by interfering with the plant’s ability to absorb nutrients, such as calcium. Calcium deficiency, by the way, is the cause of blossom end rot.
Epsom salt, usually marketed as a method to “feed” plants, is in fact not a significant source of nutrients. Rather, its nutritional value is 0-0-0. Epsom salt does not provide a significant source of nutrients for plants.
What if my plants are indeed deficient in either nutrient?
First, get a soil test. It will provide you with the information you need to help solve the problem. When dealing with suspected soil deficiencies, a soil test is important in order to ensure that you don’t upset the nutrient balance of the soil.
In some cases, magnesium may not be absorbed in soils that lack or have too much of a certain nutrient. Adding a magnesium amendment in such a case won’t solve the problem. You must first correct the issue with the nutrient.
A mineral like Epsom salts isn’t a surefire way of dealing with nutrient deficiencies of magnesium or sulfur in your garden. The highly soluble nature of this mineral means it isn’t an ideal solution for a nutrient imbalance.
Epsom salts might provide your plants with an immediate boost of magnesium if their soil is deficient, but it is not the best or even the most affordable way to deliver the nutrients to your plants long term. If your soil does lack magnesium, other amendments are preferable.
Is it worth using at all?
If Epsom salts are not ideal for home gardeners, why then is the world talking about them at all, and I suspect tradition has something to do with it. I’ve received a variety of gardening tips from my grandmother, things she learned years ago that she swears by. Some of the tips have worked, while others didn’t.
Although Epsom salt may be beneficial at times, especially in large-scale growth efforts, magnesium deficiency is not a rare occurrence. It is, however, not a practical choice for high-volume operations since it is quite expensive.
In addition to dolomitic lime, there are other magnesium supplemental options available, including potash-magnesium sulfate, certain types of manure fertilizers, and soybean meal.
If you’re not convinced and would like to experiment with Epsom salts for your garden, you can use them as a foliar spray (adding 1 tablespoon to a gallon of water) or directly on the roots of plants (about a tablespoon will suffice).
If you want to make sure your fertilizer really works, you could grow two identical plants, one with Epsom salts and one without. Let us know if you noticed a difference in the comments.
Remember, Epsom salt isn’t the same as table salt! Table salt, or sodium chloride, works best when used in large amounts to kill pesky weeds. When diluted, you can use it to kill cabbage loopers and other worm-like pests.
We all want inexpensive ways to improve the garden, but it’s important to understand the science behind any idea. Epsom salts for plants in gardens aren’t scientifically proven yet.