Epsom salt is a natural mineral compound made up of magnesium and sulfate. It’s often recommended as a self-care product for sore muscles, cold symptoms, and medicated salves. Many gardeners also recommend applying Epsom salt to tomato plants for its amazing benefits to vigor, health, and flavor of the tomatoes.
But will it actually help? Or could Epsom salt be harming your tomato plants?
Let’s sort out fact from fiction.
There is some scientific basis for the use of Epsom salt in the garden. That’s because magnesium and sulfur are very important for the growth and health of tomato plants.
These micronutrients are vital for photosynthesis, protein synthesis, and cell wall structure. So it makes complete sense that, under certain conditions, applying Epsom salt to tomato plants will make them healthier.
But making blanket statements about the use of Epsom salt in the garden is misleading and could actually be harmful. So let’s take a look at some of the claims regarding Epsom salt and tomato plants.
Related reading: 1o Things About Tomatoes Every Gardener Needs To Know
Can Epsom salt prevent tomato blossom end rot?
No. Sorry, you can’t do that.
Blossom end rot is a stress-induced disorder that affects tomato fruit. It is not usually related to a deficiency of nutrients in the soil, so adding Epsom salts won’t help prevent it.
However, magnesium will compete with calcium uptake in tomato plants. So if your soil is deficient in calcium or your pH is not optimum for calcium uptake, adding Epsom salt will actually make it more likely that you’ll have tomatoes with blossom end rot.
The Epsom Salt Myth: article by North Dakota State University
Does Epsom salt make tomatoes taste sweeter?
Epsom salt contains the micronutrients magnesium and sulfur. Growing flavorful tomatoes depends on many factors including a healthy micronutrient supply in the soil.
So by adding magnesium and sulfur to the soil, some gardeners may find that Epsom salt has a positive effect on flavor. But this is only your if their soil is already deficient in micronutrients.
If the soil is deficient in micronutrients, then perhaps a more balanced fertilizer is a better option than using Epsom salt alone.
Can you use Epsom salt as a good, cheap fertilizer?
As already discussed, Epsom salt does contain 2 micronutrients but note that they are micro-nutrients. Plants require a lot more of nitrogen, phosphorous, and potassium than they do any other minerals.
Trying to substitute Epsom salts for your regular fertilizer is not a good decision. If you want to use it as part of a homemade fertilizer, then that makes a lot of sense. But Epsom salt alone is not a good fertilizer for your plants.
Does Epsom salt treat yellowing leaves on tomato plants?
A magnesium deficiency can cause yellow tomato leaves. If the yellowing leaves are due to a magnesium deficiency, then Epsom salt may help your plants green up. However, using a balanced organic fertilizer will be more effective.
Read this post on tomato leaf problems for more information.
Can Epsom salt be used for natural pest control?
There are some claims that Epsom salt is a deterrent for some garden pests like beetles and can kill slugs. Wouldn’t it be nice if pest control were that easy?
Unfortunately, there is no simple solution for pests in the garden. Hand removal of pests and frequent application of organic deterrents like neem oil and pesticides like Bt are the best options for organic gardeners.
Have you heard other miracle claims for using Epsom salt with tomatoes?
I’d love to hear about your experience in the comments!