Using Epsom Salt for Tomatoes: 4 Things It Actually Does

Did you hear that using Epsom salt for tomatoes is THE thing to do if you want an amazing harvest? Well, it might not be totally true.

Gardening is one of those hobbies full of “expert” advice from everyone, but the advice never aligns. Some will tell you Epsom salt for tomatoes is the world’s best idea, but others tell you that it only has a placebo effect.

What’s the truth? Whose advice do you trust? Will putting Epsom salt on your tomatoes lead to marvelous results, or will it potentially cause a smaller harvest than anticipated?

Tomatoes are one of the leading plants for home gardeners. There is something so summer about tossing together a BLT with a homegrown tomato or slicing up tomatoes for a tomato basil salad.

Delicious.

Its no wonder that there are plenty of myths in the gardening world with hacks to increase the growth of your tomato plants. The most common tips surround common household items, such as eggshells, coffee grounds, and Epsom salt. Like any old wives’ tale, there are some nuggets of truth in all of these, but you have to know what is true and what is not.

Let’s look at the truth about using Epsom salt for tomatoes and how this product affects your tomato plants.

Related: How to Fertilize Tomato Plants for the BEST Harvest Ever!

What is Epsom Salt?

Epsom salt is a chemical compound called magnesium sulfate. It’s the best for a lot of bath salts and bath soaks; soaking in a hot bath with a cup of Epsom salt does wonders for your achy, sore muscles. You can find Epsom salt at most stores near you; Wal-Mart carries it in the bath section. It’s not the same as the table salt you sprinkle over dinner.

While Epsom salt might look like table salt, you should never consume it!

However, gardeners often also use Epsom salt – be sure not to use the ones mixed with essential oils! Some say Epsom salt for tomatoes works for a range of problems, from weak growth to controlling pests.

It makes sense; tomato plants crave plenty of magnesium, and Epsom salt is an excellent source of magnesium. However, the question is – does it really work as people claim?

What Are the Benefits of Epsom Salt for Tomatoes?

Epsom salt offers plenty of benefits to consider; here are a few to consider when using Epsom salt for tomatoes.

1. Adds Magnesium to Your Plants

One of the benefits of using Epsom salt is that it adds magnesium to your plants. Tomato plants need magnesium to grow properly; if they don’t have enough, they typically display yellow leaves with green veins.

Adding some to your plants is safe to ensure your ground has adequate magnesium; magnesium won’t show on a basic soil test. You’d need to send the soil away to get it professionally tested to determine your magnesium levels.

If you know your garden soil needs magnesium, provide the plants with a few tablespoons scattered over your garden bed at the time of planting and once your tomato plants start fruiting every two weeks. Foliar feeding also works great as an as-needed boost of magnesium.

2. Improve the Flavor of Your Tomatoes

Homegrown tomatoes taste significantly better than store-bought tomatoes. Flavor matters! One of the reasons I spend so much time growing tomatoes is the taste difference. I could go to the grocery store for bland tomatoes if I wanted bland tomatoes.

Epsom salt improves the flavor of your tomatoes. Magnesium and sulfur are essential micronutrients your tomato plants need. Magnesium plays a star role in photosynthesis and chlorophyll development, and sulfur helps the production of proteins and enzymes. While you only need small amounts of these micronutrients when compared to NPK, they work together to ensure your plants are healthy.

Healthy plants with a solid supply of micronutrients increase your plants’ health. You’ll find that they taste even better.

Try adding small amounts of Epsom salt to your watering can; this ensures the magnesium is available to your plant quickly. The recommended dose is one tablespoon per foot of plant height. You can break this up into multiple watering applications each week.

3. Helps Plants Intake More Nutrients

You know how important it is for your plants to be well-fed. The more nutrients they have available, the better they grow. While magnesium is only a micronutrient and little is required, its presence allows plants to uptake vital nutrients, such as nitrogen and phosphorus.

If your plant suffers from a deficiency, it won’t be able to absorb the essential nutrients truly needed for growth. All it takes is a small application before planting or during the growing season to ensure your plants have the ability to absorb all they need with nutrient uptake.

4. Improves Overall Growth

Humans and plants aren’t entirely different. Both humans and plants need nutrients and vitamins to grow. Humans are healthier when we have a balanced diet with all the vitamins we need.

Tomato plants (and any plant) are the same way. When you provide your plants with everything they need to grow to their maximum potential, you end up with the tomato harvest of your dreams.

The opposite is the same as well. If they lack nutrients, the plants are lackluster in harvest and experience other problems, such as diseases and pest infestations. So, using Epsom salt for tomatoes ensures your plant grows taller, produces more fruit, and is overall healthier.

Use Epsom Salt When You Spot An Issue

One of the main problems you might notice on your tomato plants is yellowing leaves; it’s never a good sight when your plants’ leaves start to yellow. That’s a clear indication of a problem, and there are plenty of reasons for yellowing tomato plant leaves. Some problems include too much (or too little) water, fungal diseases, pest infestations, and much more.

If your tomato plants experience a magnesium deficiency, yellowing leaves may be a sign, and it’s easy to get fixed if you have Epsom salt on hand. One of the most common signs of a magnesium deficiency is yellowing leaves with green veins, a condition called chlorophyll. This is because magnesium is a part of chlorophyll production, so a deficiency leads to yellowing leaves.

Related: Did You Find Tomato Leaves Turning Yellow? Here are 10 Reasons!

If you notice signs of a magnesium deficiency, create a foliar spray by mixing one tablespoon of Epsom salt in one gallon of water. Then, spray the leaves on your tomato plants. Be sure to only do this on cloudy days; sunny weather may damage your leaves.

Are There Side Effects of Using Epsom Salt for Tomatoes?

Yes, there are potential side effects if you use Epsom salt for tomato plants that aren’t deficient. The benefits listed above are only benefits if your tomato plants lack the proper amounts of magnesium. Extra doses of magnesium are unnecessary and may cause more damage than good when too much is added.

Excessive Epsom salt added to soil leads to root problems because the magnesium accumulates in the soil, leading to a macronutrient imbalance. Another potential side effect is that Epsom salt can spread into the environment, acting as a pollutant in the water.

Too much Epsom salt is never a good thing; that same goes for nearly everything else in gardening as well.

Test Your Soil Before Using Epsom Salt for Tomatoes

Since you typically should only add Epsom salt when your soil needs it, a soil test is healthy to determine if your soil has a potential magnesium deficiency. If you prefer not to perform a soil test, stick to a general fertilizer with the recommended dose, which is likely to resolve the problem.

What Epsom Salt for Tomatoes Won’t Do

We know that the use of Epsom salt has benefits in your garden, but don’t listen to anyone who claims it will solve all your problems.

It won’t; the myths are all smoke and mirrors, even if someone swears it works. Here are some things that using Epsom salt won’t do for your garden.

1. Prevent Blossom End Rot

Blossom-end rot is a condition you never want to experience with your tomato plants. It affects the tomatoes’ fruits because your plant cannot absorb enough calcium. This leads to a deficiency, causing the rotting of the fruits.

As someone who has experienced blossom end rot, I know gardeners try everything to fix the problem. Epsom salt is not a way to fix it, mostly because the problem isn’t the soil, nor is a calcium deficiency the problem. Instead, blossom end rot had more to do with improper watering, leading to calcium uptake problems. Your tomato plants may end up with blossom end rot with plenty of calcium and magnesium present in the soil.

2. Help Tomato Seeds Germinate

Germinating seeds isn’t always easy; sometimes, it’s downright frustrating. Tomato seeds are evidence of the magic in nature; these little seeds hold all the nutrients needed for plants to sprout and begin a new life.

Nature doesn’t need our help with nutrients, vitamins – including magnesium – when germinating. So, any application of Epsom salt is simply useless when it comes to seed germination.

3. Stop Tomato Plant Pests

When your garden beds face attacks from garden pests, you will try all sorts of methods to get rid of them. The last thing you want is for all your hard work to go down the drain.

Some websites will tell you that Epsom salt acts as a pest control for caterpillars, flies, grasshoppers, and other tomato pests. However, no evidence supports these claims, and chances are, if you use them, you won’t have any positive results.

4. Feed Your Plants

Epsom salt is included in the list of tomato fertilizers because it fixes magnesium deficiencies. So, that sounds ideal, but that doesn’t mean Epsom salt truly feeds your plants.

Magnesium is a micronutrient, and tomato plants need magnesium in far lesser amounts than it needs nitrogen, phosphorus, or potassium. It’s important to know that fertilizer should give the plant a range of nutrients needed for growth or core nutrients needed for a specific purpose in the growth cycle, such as fruit production.

Magnesium may be important, but it will not give your plants the nutrients needed to act as a complete fertilizer. Healthy plant growth requires macronutrients; micronutrients are little boosts that help overall health.


Don’t believe what everyone tells you! While using Epsom salt for tomatoes offers some benefits, it’s not the end-all-be-all in the garden. It will only cause minor changes, so don’t stress out if you forget to use it.

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